I'm sorry you are going through this. I myself am in somewhat of a similar situation. I would like to point out that most addicts cannot support their habit by themselves. I suggest not giving him access to your bank account because as you said you know what will happen if he has access to it. If he says FU and instead of direct deposit gets hard checks then let him do so. It is his choice to spend his money however he sees fit and as long as he is in active addiction then that means he will spend most if not all on drugs, but you have a choice of keeping him away from your money. If he is not helping financially then although it may be hard I would send him on his way.
Him saying that your and everyone else's lack of support is why he is acting in such a way is exactly what you said. The blame game. He chooses to act, say, and think what he wants. You have no control over that.
I understand much of what you say because my boyfriend is an opiate addict and the father of my daughter. He also has BPD. He is prescribed Prozac but doesn't take it because of his addiction. He also goes days where he wants to do nothing but sleep. He doesn't want to find a job, be a father, or deal with anything else that life is throwing him. That is his issues though and not mine.
I commend you for wanting to go to ALANON. It will help you a lot. I will pray for you and your little one!