Hi,
Don't ever forget that you cannot do a thing for him. And what Smoke said fits what I am doing right now with the Beav.
I once had to give up the notion that I could stand having him around while he got good and ready to straighten up. Keeping yourself in the middle of the chaos is not support, it's collusion. Support is "you can do it", and it can be done over the safety of the telephone.
There are ways to be supportive without compromising yourself. And if after every encounter with him you find yourself feeling guilty, you are probably being manipulated! I just learned that one myself and I am an old broad...you are doing great!
Hugs,
JT