Help me understand his apathy

Hi, new here, new to the ideas about ADHD too!  Currently separated from my husband for no very obvious reason.... he left but can't explain why.  He also says he is 'comfortable' with not understanding what went wrong.  I am devastated and hoping we can reconcile.  He recently mentioned the idea that he might be affected by ADHD, I don't know how much he has looked into this but I've been researching it and the 'parent/child' relationship that develops often between affected and non-affected spouses fits very closely with what we both seem to have experienced.  I'm wondering if the total lack of interest in working on a reconciliation could be an ADHD effect?  I've read and watched a lot of material on couples issues and it seems that often even couples who appear to hate each other are still willing to work on their marriages.  We definitely don't hate each other, there is a lot of warmth between us, but he seems terrified of feeling whatever the bad feeling was he had before he left.  I'd be very happy to receive advice on how to move forwards - at the moment my plan is to play the part of the audiobook on ADHD and marriage where it briefly introduces the feelings that the two halves of a couple tend to experience and hope that it gives him the same sort of lightbulb moment that I had when I heard it.  Thanks in advance for any input!