Apart from the poison persons, do you find these meetings helpful? Are you required to go to them? From the 12-step people I have seen, a lot of them have a strange ego effect now they think they have found "the truth." They can be very self-righteous and judgmental -- in other words, jerks like the people in your group. Everything is fodder for their dogma. Are there no reasonable sorts at your meeting? Perhaps you can find another meeting (if you're not in a small town) or some other kind of support group?