99.9% gone

I haven't been on here in such a long time because I've been immersed in both individual and couples therapy, but I really could use some help from others in the trenches please. After 17 years of a difficult marriage my husband had an "awakening" because he realized that he had lost me. This after his emotional abuse, affairs, and his telling me he wanted a divorce countless times. Now he's a "different person" and he says he could understand my leaving the old version, but if I leave this new guy I am quitting on him and our marriage and he doesn't think he could forgive me for that. His previous doctor wanted to evaluate him for bipolar disorder, several other professionals have wondered if he is bipolar or narcissistic. Our shared psychiatrist (he was deeply concerned about my health and put me on anti-anxiety meds) has said that it doesn't matter what else he has going on besides "severe ADHD" as I really need to take care of myself and meet with a divorce attorney to find out my options. (His ADHD is severe as he rarely sees someone his age with such strong inattentiveness, impulsivity, and hyperactivity.) Our financial situation is terrifying thanks to his poor business decisions and extreme spending. We have two children (ages 11 and 13) and I've honestly told him that my fear of divorce only has to do with their well-being, our finances and the awful process of divorce, but not losing him.  He is so relentless and forces me to have conversations about us which last for hours. I'm to the point that even if he has legitimately changed his personality, I don't want to be with him. I don't see how I can ever trust him to be faithful. I'm so angry at myself for staying this long and putting up with his treatment of me and our girls. He's finally stepped up as a father and I hang on to the fact that if I'd left earlier they wouldn't have a relationship with him. I'm scared to finally end it. I'm a child of divorce and of an alcoholic, it's so difficult for me to stop trying to fix it even when I'm this far gone.