Help me understand as the non-ADHD spouse

My husband left just over a year ago and I haven't known why.  I've finally stumbled upon the ADHD in marriage information and it tells our story, except that he was the one who left.  He is terrified of feeling trapped and controlled and at the moment is utterly disinterested in looking at reconcilation.  We have met up a couple of times recently and have talked for several hours, from my point of view getting on very well and having quite a nice time despite the weird situation.  Logically he seems to recognise that I haven't been a horrible controlling harpy but emotionally he is scared, shut down and still in the 'child' role of the parent/child relationship.  I want to suggest that we explore the idea of being friends and maybe do some fun stuff together so I can become associated with nice things (and dopamine) rather than just being the boring one who looks after the finances.  Any suggestions about how to go about makint this suggestion in an ADHD friendly way?  I'm really struggling to put myself in his shoes to see what sort of thing might work.