Wife cheated on me three times what to do now

I have been married about 20 years ago and have 4 kids� two teenagers and other two 9 and 7 years old. My wife cheated on me twice for which I caught her but don�t know how many times she were doing this to me in this 20 years of marriage life. I am very upset feels hurt cannot eat and sleep well these days.
There is an age difference of 18 years between us. She is very younger than me. She is my first cousin. When I married her she was a teenager and I was more than thirty years old. When we had fight she always used to say you ruin my life. Why you married me in that younger age and also blame me for her cheating on me. She was from a very poor family and less educated. I am an undergraduate from university. I was alone my mother died when I was just 3 years and my father died when I was studying in university. No sister and brother and no other close relatives. So I was looking alone for someone to marry. I was scared to marry to a stranger woman thinking don�t know how will be her behavior with me. So I decided to marry from my own relatives. She was very beautiful but very younger than me and less educated. After some thoughts I decided to marry her thinking she is my cousin and will be suitable for me and she will respect me. I talked to my Aunt and she agreed happily. They were very poor so I did all the marriage expenses. I got a good job and lived very happy for six years after that I moved to Canada and got a good job here too. I gave her all necessities of life and loved her very much but soon I found she is very selfish always thinks about herself likes always shopping and thinks always about have more money. She is a very lazy person sleeps more than 12 hours a day. Just do cooking 3 times a week and cleans may be just one time in a month or when someone visit our home. She likes watching TV most of time and not giving enough time to me and kids. I always take care of her and loved her because she was my cousin instead of all these short comings she had.

I was suspicious about her from beginning of marriage but never got evidence and also never tried to get evidence because I always trust her. I become suspicious at some occasions like I remember after one or two years of marriage during travelling in train I noticed her talking and flirting with a stranger young man. I got mad and warn her don�t do that again.

I became suspicious when I saw her alone with a young man a relative of her sister- in law at my home in my absence when I was coming home from work.
Here in Canada when we were living in a basement I saw her flirting at various occasions with Land Lord. One or two occasions I saw her with Land Lord in the basement alone when coming back home from work. If he was there for some work she should not allow him in my absence and then Land Lord brought gifts for her and my kids I become very suspicious about her.

After moving in our new house in 2009 I did surprise visit to home during lunch time I noticed door was locked from inside I couldn�t open it with my keys. When she opened the door after a long period she was surprised to see me during lunch time and was looking ashamed. I asked her why you took so long to open the door she said she was in basement doing laundry but I saw her she was looking outside of back door again and again. I suspected that there was someone in my house with her in my absence when I asked her she said no one was here.

In 2009 she was working as cleaner in Downtown I noticed she was getting extra ordinary prepared when going for work then I suspected her. I also noticed a difference in our sex life which suspects me that she also had sex with someone but she never admitted. One day I was checking her cell phone bill I noticed repeated calls to a phone number and lengthy calls of more than hour. I asked her about those calls she told me I was talking to my female friend. When I investigated that phone no it was a male. I confronted her and she admitted I was just talking on phone to him but I was suspicious something is wrong. Then I noticed she was going outside alone saying I am going for shopping with my female friend or going for Quran Khatam or going for Naat Khuwani etc but later on I found she was a big lair.

One day she asked for my permit ion to go for Quran Khatam to my female friend�s home. I was suspicious about her so I said no you can�t go alone and I went for work. When called home from work kids told me she is not at home. I got so mad and we had a big fight. I told her I am giving you divorce she got upset and tried to suicide. I have to admit her in hospital. Then we went for counselling and I forgave her.

I took her cell phone and asked her to quit that job and I forgot everything and starting living happily again.
When I got her trust back in 2013 she asks me for cell phone and also said I want to work because getting bored at home alone when kids go to School. I gave her permition for job and gave her cell phone back thinking that she would have learned a lesson that making contacts with other man is haram and a big sin in Islam.

In 2013 and 2014 I noticed some suspicious activities again. For example I noticed at night when I was sleeping she would do chatting with someone when I asked she would say I am listening music but later on I found that she was chatting with her lover. Then I noticed she would call me from her work place that don�t come to pickup I will come with my female friend which later on I found was her lover.

One day I came home at lunch time as a surprise visit and found that she was not at home. I waited for her and she came at 3:00 PM when asked her she said I was gone for applying job but latter on I found that she was telling lie instead she gone with her lover to buy a cell phone and sim card for which later on I found a receipt in her purse and also heard about that phone latter on when I recorded their conversation on phone.  I asked how you bought those things because they are not on list of credit card. She said I bought by cash but when I showed her receipt which was paid by another credit card she admitted then. Usually when she goes somewhere she always asks my permition but this time she didn�t which made my suspicious converted into reality.

Now it was proved that she was cheating on me second time. Then I started checking her cell phone again and found that it was password protected. I asked for password she said it�s my privacy I said there is no privacy between wife and husband. She showed me the phone after checking found that she were deleting logs. Then I called cell phone Company to get call records. According to that cell phone call records she was calling a phone number repeatedly from Aug 2014 to Nov 2014 with some calls of more than two hours duration and repetition of more than 15 calls a day. When I investigated that phone number found that she was talking to a man. When I showed her all proves she admitted someone loved me but now he is not. He cheated on me and loves some other woman. I got mad what you have done with me and we had a big fight again.

I will never forget Nov 20 2014 I was working in that area where her workplace is and after finishing my work I hide in parking of her workplace area and when she was off from work I saw her with a man who was giving her ride to home later on she admitted that he was my lover and I went with him outside 5 times in last six months.

On Nov 27 2014 she cried in front of me and begged for forgiveness. I am a soft hearted man and forgave her one more time and told her to promise that she will not contact that man again and discontinue all contacts with him. She said change my cell phone number which I did but I was keeping an eye on her.

After some day I noticed she was contacting him by land line phone. I bought a recorder and on Dec 18 2014 when I was going to work I turned on recorder. Then I heard their phone conversations in which she was telling him to marry me and at the same time she was telling him that you cheated on me and you hurt me. I gave you proves of cheating on me etc. So what a surprise for me that she was cheating on me and her lover was cheating on her. This is called Tit for tat. So technically she was cheating on me third time.

After few days she again cried in front of me and begged for forgiveness and told me to give her another chance. I forgave her one more time and started living happily but still I had feelings from inside that I will not trust her anymore and always suspicious about her. Sometimes I try to close to her and show intimation but other times when thoughts of those occasions come to my mind I hate her and don�t want to see her.

Few days back I have seen her again with a man playing bingo on a table in ACH hospital where she was with my daughter who was sick those days. I lose my mind again and feeling very sad and I hate her and don�t want to trust her again. She suggested for counselling.

On Apr 13 2015 we went for counselling but during counselling she blame on me for all cheatings and also said she does not love me in front of counsellor. Then I got very upset decided to go for separation and now we are living separate but in same house due to our children.

So this is story of my marriage life. I am very upset feels hurt and need some advice what should I do now with this woman.