It is interesting that H agreed to meet you for a visit in the park. The conversation I believe was benifical. His responses show a lot of self awareness, about the pain and difficulties he has caused you, and that he is experiencing. There is even some responsibility for his actions. This is encouraging.
Like all endeavours - do more of what works and less of what doesn’t.
He positively responded to your invitation for a visit. Give him some time and space; see if he reaches out. If not, ask again. Perhaps in a few weeks.
The next time:
“I simply wanted today to be about him spending time with the dog and seeing how he was. Unfortunately that did not last long...….”
Do that. Just spend time with him and have fun with the dog. The previous conversation probably gave him enough to think about for a while. If he brings something up, just kind of let it go and “spend time”. Of course listen and acknowledge, but no need to have a R conversation so soon after the last one.
H seems to be in a different place than most. Remaining calm and pressure free may just help him have a few more pieces to fall somewhat in to place, or at least into play.
From my point of view, things went really well. I wish my spouse had such “feelings” and awareness.
You’re doing fine.
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.