He's the polar opposite of non functioning - can this be ADHD?

I am a non ADHD spouse. My husband says he has probably had ADHD since childhood, but has never been diagnosed. He is trying to self-manage any less than desirable traits that he is aware of. Brief background – he was married, divorced, remarried then widowed. I was widowed. We met and married in our mid 50’s. During courtship he was so very fun and treated me like a queen! After about a year he started losing the ability to filter some unnecessary hurtful commentary and there were some angry outbursts. We were already engaged to marry at that point, and by the time we were wed the honeymoon was already over. Now I am focused on avoiding criticism, and I wish I could stop taking the diminished attention personally. Intimacy is all but gone. There are now many topics that I consider to be off limits and I have become disconnected as a defense mechanism. I’ve tried talking to him about our communication difficulties but I always manage to put him on the defensive. These conversations have not gone well for me and I end up very upset. I know I am not a naggy person and I give a lot of thought to how to be considerate and tactful, but now I’ve learned here that my words have surely had undertones – very good to know! Regardless I've never had anyone be so hurtful to me. He has talked some about this but is not very receptive to seeking help so I want to be very careful in my approach. Now after reading on this site I don’t know what to think because he does not exhibit what seems to be the most common ADHD trait – an inability to follow through or contribute. He is the polar opposite of those experiencing issues getting things done around the house. Many things have to be done as soon as they present themselves like laundry, reading and deleting emails (even going to the trash folder to delete permanently), and tossing things (that others want) into the trash. He is like the energizer bunny around the house and works harder than most who are decades his junior. But he does know how to relax too. He is usually early – I don’t think he’s ever been late for anything. So there is no issue with him pulling his weight around the house and then some. I on the other hand now do many things I never had just to avoid any negative comments. When I read about the hyper focused courtship I cried a little. That is us for sure. I know he loves me very very much and it would matter to him to know that I am no longer especially happy, but at the same time I don’t think he can fathom anything he might do to change this. We were lucky to find each other late in life and I don't want to waste precious time before we begin to figure this out. So should we be looking into something other than ADHD with the hyperactivity and over achieving? I’d appreciate any thoughts as I may only have one chance to inspire him to seek help and want to have the best chance of getting to the right professional.