I'm glad you are getting help and are honest with yourself that you have a problem.
I think it is the case often that when we don't know how to cope with, say, our upbringing, and the unhealthy influence our family has upon our lives, it can be easy to turn to a mind altering substance to escape the pain we feel.
As children we are helpless. It's different than when we as adults make a choice (even if it is the best we know how to do at the time, this is a whole other discussion really) to have any relationship with someone. So it can be easy to just stew in anger over our childhood. We didn't have a choice.
But even your parents are the way they are for a reason, right?
Once we are adults ultimately it is up to us.
I understand. There have been many falling outs in my family. And though I understand that they are the way they are for a reason just as I am, sometimes I have to minimize contact and even break it completely.
I think because you need their help right now your anger is raw. That is a difficult situation.
Keep posting here.