hi, just looking for some advice...

I have been with my boyfriend for 9 years off and on.  He is emotionally, physically abusive.  Last week he hit me in front of our son.  I told him to leave.  But he didn't want to.  We had a son about 1.5 years ago.  He has tons of debts - credit cards, gov't taxes, etc.  He doesn't do his taxes, doesn't claim any money that he makes, doesn't pay bills on time (or at all).  We have been living in our current apt for 3 years, and he has never paid rent on time - not even once.  This week, he went away to "work" but he said he didn't know where he was going, and his boss didn't know either...?? (he booked a motel apparently...) How can he expect me to beleive him?? He says that I should trust him...how can I trust him when I can't even trust him to not hurt me. 

anyone had a similar sitution? was it ever resolved? any adivice?