MHO is, do NOT go to an attorney just yet. IF he wants a D, let him do all the leg work.
It sounds to me like your H is still in the "discovering ME" mode....everyone doesn't come thru MLC in 6 mos or a year, it takes longer for some and maybe your H just needs more time.
I would definitely continue the friendship. I would definitely continue the socialization with him and the kids. Don't stop anything that's good between the two of you. Let him ride out his journey...and YOU finish yours.
This is NOT THE END...it's another turn in the road. YOU'LL know when it's time to get off the highway, and from what I'm hearing here, now is NOT the time. T2