Yes, em, I suspect he is....there were a few glimmers a little while ago iirc before he romped back to selfpity and rage. And he has a lot more self repair work to do doesn't he? It sounds, reading between the lines, as if he is apologising for his behaviour while drinking specifically but not other things? So, maybe a partial look?
If you don't know what to say, it's ok to say nothing until you do. Or indeed to just say nothing. Or to say you don't know what to say lol.
Who knows, maybe he is working some 12 step programme....if so, he'll know (or learn) that people have no obligation to respond just bc you apologise and would like them to. That an apology is not a downpayment on a future favour or a magic erasing wand lol. And you will see if his apology is worth much by how he responds if he had an agenda which didn't get met
....which sadly is possible bc I think your xh is in a real pickle and wants help with his daughter bc he doesn't know what to do....so if you do nothing and he flips back to anger or selfpity, well that will tell you quite a lot about how genuine his recovery progress/efforts are.
Out of interest, has he apologised to anyone else like your older kids as far as you know?
And does he still drink?
T: 18 M: 12 (at BD) No kids.
H diagnosed with severe depression Oct 15. BD May 16. OW since April 16, maybe earlier. Silent vanisher mostly.
Divorced April 18. XH married ow 6 weeks later.
"Option A is not available so I need to kick the s**t out of Option B" Sheryl Sandberg