I think some people just naturally gravitate toward drama/passion filled relationships. Whether its good for them or not. Sounds like your ex is one of those guys. Or at least he is recovering from 8 years of it, which is a long time in that environment. He must have been getting something out of it. If you are her personality opposite, that might have actually been a negative on you. Not fair or reasonable, but emotions rarely are.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh