Imago was also suggested for us, before my H recovered and it wouldnt work because he lacked the skills for being able to handle MC in a healthy way back then.
I would put the emphasis on your codependancy group
and his getting into DBT.
One thing we discovered, as a couple, was that when he was recovered from BPD and I from codependancy, we did NOT have issues as a couple. We were quite compatible and years later, continue to be going very solid and strong!
This is great progress, by the way...get working on you and let him get into DBT..it takes alot of time and hard work, but in a few years, you could be much, much happier!