Video game boyfriend...

My boyfriend never leaves his room, all he does is play video games. We have 3 kids, and he doesn't work right now, he just expects me and his parents to pay rent. I don't make enough to pay are bills by myself and I hate relaying on his parents but don't have another option right now. He only comes out of his room to get food and sleep. When I work he does sort of watch the kids, and keeps the house clean most of the time, but the second I come home he takes a nap or he is in his room on his game, if I try and talk to him, the kids make to much noise, or even enter the room he just gives me an evil glare or punches his chair and curses... Most of the time I come home and dinners never done, there has been times I've come home and the kids say he never made them food all day. :( right now my kids and I are all sick, and he hasn't helped with anything. I feel single and all alone, yet trapped and idk what to do. I want to leave him, but don't know how.