I think Aries is right about other drugs - as I was reading your description of how crazy he is acting, I kept thinking this sounds like an out of control meth user. Its possible drug use came in the mix after he got out of rehab & started to really change for the worse.
I am not saying he doesn't also have a wicked bad drinking problem.
I know from my own experience everything can be all fun times with our addicts. That is until one day the wheels come off the tracks. It can happen suddenly without warning. Can happen repeatedly. Major train wrecks. It sucks, but there was honestly nothing I could do to stop any of it. Those same type of train wrecks are still happening today with her. I am long out of that picture.