He's had time to get over his suicide attempt, hasn't he? Well, why can't this "other" woman take care of him? Since she seems to enjoy his company so much, let HER have him. Kick his fanny out! You don't need this kind of abuse, and he seems so much happier in HER company so send him to her.
You poor thing. You've suffered so much for so long, you don't need this any longer. Why should YOU have to nurse him any longer? All he's doing is continuing to abuse you and break your heart. I know you feel you should keep nursing him, but he must be pretty much back to normal by now -- at least physically. If he needs more psychological help, SHE can take him or he can ride the bus or whatever transportation that is available.
I just can't see you having to put up with this any longer. You've suffered plenty already. Maybe I'm being too hard-hearted, but so many women continue to suffer for months, years because of guilt -- because they feel they HAVE to. Well, I say they don't HAVE to -- it's time to dump the guilt and have a life of your own. You didn't CAUSE him to try suicide. It wasn't YOUR fault. That was HIS decision, and ONLY his.
So tell him to go live with her. If he won't leave, then why don't YOU? You don't have to stay with him. You can leave any time you want. Start a new life! It might be tough, but you can do it.

It's better than the one you're living. God bless and please take care. Hugs, Lee