I'm working on not letting myself be drawn in as well. Especially into arguments. I wish I could give you solid advice. Unfortunately, sadly, what is helping me is that... I just don't care so much anymore. I'm fed up.
Another thing that really helps is to remind myself that there is no reasoning with my AH... therefore, all I'm doing by getting sucked in, is making MY life, my day, harder and more miserable.
Wishing you strength.