Burnt out & anxious

Hi, reading everyone's posts is so helpful & makes me realise I'm not the only one experiencing the same frustrations. I've been with my husband for 20 years. The penny dropped about 5 years ago that he likely has adhd. It explains so many situations, misunderstandings, arguments, confusions over the years. To cut a long story short, he remains undiagnosed. He is hard-working and a great dad, which makes it so hard to consider leaving. However I'm finding it so hard day to day to feel calm around him. He is restless, easily frustrated, quick to anger, impulsive, defensive, intense, and obsesses over details. Anything I do in the house isn't quite good enough, because I don't focus on things with the same intensity, so I never seem to get anything right or be good enough.  He dominates conversations and frequently talks over me or interrupts. I talk and he just walks out of the room. I now just stop mid sentence but he says he's still listening. I'm a teacher, I spend my day projecting my voice and it's exhausting. I never feel I really have his full attention. If I disagree with him, on something as simple as a paint colour, he gets defensive as if I've personally wounded him. The simplest of requests can cause him to flare up. And of course there are the regular lost keys, wallets, unlocked doors, unlocked car - it actually got stolen and he still fails to remember to lock it, lost jackets, glasses etc, fast driving, which at times is nerve wracking. 
I see so many articles etc on how to support your adhd partner. I'm the one who needs the help, I'm done being the one to be accommodating and understanding when he just seems to carry on without taking any responsibility. 

I'm exhausted and want calm.