Decieved

I want your knowledge regarding my rights within Islam in this case please.
We married 20 years ago. He took UK citizenship through our marriage. Within that 20 years of marriage, he worked for just 2. My work supported us. We have a teenage child.
Our marriage began failing around 2011 and we ceased marital relations. I took a job abroad. He followed me, saying he would not leave his child. He moved into my house (the spare room) refused to divorce and refused to leave. Being overseas I had no support from authorities who refused to get involved. He goes out at 8am in the morning and returns to sleep in the spare room at 9pm. Weekends, he forces our child to spend time with him, refusing to allow them to see their friends.
He and I speak only to discuss the welfare of our child. I have no idea even now where/whether he works, and he refused to provide any monetary support for our child until mid 2014. Since then he has provided some few dollars per month. I pay everything else., including the house rent living costs, and school fees.
Despite my frequent requests for a divorce he refuses, and also continues to refuse to leave my house, sleeping there at night although he has no clothes or possessions there, not even a toothbrush.
6 months ago I learned that he married another lady in 2012. He brought that wife over to the country I live, he has rented a house not far from mine, and she just gave birth to a child.
I had no knowledge of any of this until I stumbled across evidence accidentally. He has not told me this himself. Our child is not aware of this. I have not told him I know yet as I am unsure how he may react and I want to be armed with knowledge before I speak to him about it.
I realise that there are many opinions about this, but I just want to know the Islamic rights that I have here. I want to divorce this man as soon as possible. He refused to divorce me so how can I divorce him and how long will it take. I want him out of my house and out of my life. There is no way back ... He has decieved me and my son... lied to us ... for over 4 years and I want out. Please tell me what Islam says about this.

You can find a library or stadium for your child while you're away

Thank you for the responses and support that most of you gave. I want to update and ask another question...
I came back to England and the man stayed overseas. He finally agreed to divorce me and arrived in England with a divorce deed he said he prepared in Pakistan. We signed it, he orally divorced me (said three times) and he told me it was over. Of course this is what I want, but now I am confused as to whether this divorce is recognised in UK, or if I have to get a divorce here as well.
Can somebody tell me whether I am divorced in the eyes of the law in England?
Thank you