How do I leave?

Get a restraining order immediately. And have whoever in your family that owns the house start eviction process on him so it's a double whammy.

If he's physically abusing you, you need to get him out.  Police report, restraining order, lawyer, file for divorce.  And DON'T back down.  Then, once he's out, change the locks.  But, remember, pissing off an abuser makes them more angry.  Especially since he has a substance abuse problem.  When he goes in front of a judge for the abuse charges, make the court order him drug and anger management counseling as a condition of his sentencing.  And know the cycle of abuse...look it up.  You will start to feel guilty at some point, because he'll manipulate you.  Don't fall for it.  Know the "honeymoon phase" is coming, and it will end abruptly.  Abusers can't control their impulses, and will repeat the cycle until they are forced to address it.  Watch your back with him, but make sure and follow through.  Tell all close friends what you are doing, where you are going, so people know to check on you frequently.  If he knows he's being watched, he's less likely to do something stupid.  Be safe!

Sarah, if you are in fact being abused, for your daughter's sake as well as yours, get out.

If the house belongs to your family (i.e., they own it), they can order him to get out -- he's essentially a tenant and has no rights to be there except with their consent.  And if he doesn't leave, get the sheriff and a restraining order.  That will work until you can get a petition filed and start the formal legal process moving.

Talk to a qualified attorney and lean heavily on your support network of family and friends there in your hometown.  I am sure they will be helpful and see the terrible conditions you are forced to live with.  We're all behind you here too :)

if he is abusing you, call the police. get a restraining order. press charges. call a lawyer and keep him away from you and your child.  abusers do not slow down...they increase the abuse.  please contact an abuse help line today.  the white box on this page, with state divorce laws and calculators, has links to abuse help lines and phone numbers.  they can offer more concrete suggestions. but please get yourself and your child SAFE.