It is Him not You! You have been doing well, he will continue to be who he is no matter who he is with----oh, I know how strong the pull down to the couch can be---you have a Life worth fighting for---and you are in a better place without him. HE WILL NOT WIN. And remember, when one person/emotion seems to :"win" it really doesn't negate all else. It feels that way but that is a lie you have learned to tell yourself, it is all or nothing. No. It is simpler and more complex than that.
Maybe you should send the couch to the dump in celebration.