I agree with all of the above. Stop having sex with him it is messing with you even more and get out of there anyway you can. Go home if you can where you have your support network. If you can't find another place to live, any where even if it's not idea. Where you are now is less than ideal.

You can't start to grieve properly until you are away from him.

Best of luck and keep chatting if it helps.

tt