Should I have sex with my Husband

My husband and I have been going through it for about a year now. I have actually told him that I no longer want to be with him. I am not financially able to actually leave and get a place for myself and our two kids. He literally said that he would make the house hell until I moved if that's what I decided to do. I told him I wouldn't leave and we would work it out, but that is a lie. I am still secretly saving up to leave. I have to walk around the house like I am happy so my kids won't be in hell. I have been doing this for about 3 months now. The only thing I have not done is have sex with him. I can't bring myself to have sex with him. Just the thought of it brings me back to a time when my foster father used to take advantage of me. The only thing is that tomorrow is his birthday and I know that he will suspect something if we do not have sex. You all I am really stuck between a rock and a hard place. I really don't know what to do. Help Me!!! EDIT: I tried to communicate with him. I told him I was unhappy and no longer wanted to be with him. I told him that we should both prepare to leave. Save money and start looking for our own place. I tried to do the right thing but he decided to be controlling about the situation. Now I have to take things into my own hands to make sure that my kids will not see the evil that can take over this house. Another thing, if I was able to stay with family I would have done that a long time ago!