Divorce Support Forums: Wanting Separation but if He wont go, then what?

I have been married 11 years and we have one child together who I homeschool...grade 3. Our marriage has been basically over for many years but we both just live together still out of convenience I guess...neither will go. He works full time and I havent worked since our son was born...he wanted me to be home with him so I quit. Now, I can hardly stand him being here and neither can our son! It's so nice and peaceful when he's not here but when he's here there's always arguing...either me and him or our son and him. He is always unhappy about something or finding fault. We cant stand it but he refuses to leave the house and I cant support myself or son so what can we do??? Can he be ordered out?? Can he be ordered to pay support and/or maintenance? What about the bills?? I'm trying to find a job but I have arthritis so bad that I dont know what I could even do now. Any advice or am I just in a hopeless situation....