Abandoning him at this point will probably make things worse (for him), but that's not necessarily a bad thing. You've heard the expression "It gets worse before it gets better." We enablers are the ones slowing down the natural course of actions that needs to happen in our addicted loved ones lives. Your ABF's family and friends have all turned him over to whatever happens and you're the last hold out to letting him experience what he needs to experience. It is very hard to let go because we want to shield people from the often less than ideal effect of the consequences they have created for themselves--but we have to if we want them to have a chance of getting better. This battle is your boyfriend's battle to fight, not yours. He will either rise up to the occasion and get help--or he wont. It is totally up to him. As an enabler, we slow the process of seeing what our addicted loved ones are truly made of. Some will make the choice to get help, some wont.
Find out all you can about enabling and don't do it. You will not be abandoning your boyfriend by making him face all the consequences of his actions on his own two feet. You will be offering him a chance at recovery. Enabling our loved ones is absolutely something we must not do if we want what is best for the people in our life.