I get ansy whenever I hear someone describe themselves has having character flaws, etc..., as usually this involves sizable guilt and (more troubling) the potential for the person to see themselves as not changeable. To me, personality isn't as free-flowing and changing as the clouds in the sky, but neither is it set in stone.
It must feel good to hear him owning some responsibility. The trick may be to not be seduced into allowing him to own all of it, for that would likely lead to an eventual place of resentment on his part. Every human R involves an interaction, so your exploration of your own role seems spot on. Maybe he's trying to take sole responsibility in response to your obvious pain?
