Why can't I have the courage to leave?

I married a man 10 years older than me.he's prev. divorced.we've been together 5 yrs.he had lied to me about stuff.he was doing some drugs for 2yrs and didn't tell me.we have a 4 year old girl and he treated me bad while i was preg.i had serious medical complications but he still treated me bad.he has an anger problem and just started therapy.sometimes he gets mad at me and takes off to a friends place where they drink alot.i don't know what they do.he has put me down with his firends.he even left the night before we had a vac.planned and didn't come home all night.i'm just tired of it all and last night i asked him to leave and not come back.i know i should leave bec all this is making me sick.i have had an illness for 4 weeks that just wouldn't go away.i'm scared to leave bec i don't have family around and i'm afraid he will not pay for anything for the kid.i can afford a place since i have good job.i'm alot more educated than him,although he makes more working for the movie biz.