FYI- I just began looking at this website today. I would read the Articles about Rejection Sensitive Dysphoria (RSD), in particular, I would read Rejection Sensitivity ADHD Marriage/.
I would ask him to read this and maybe some of the articles to see if they say what he has trouble articulating. I would present this request as being about your need to understand. These articles may be a way to help him communicate.
One of the symptoms of ADHD, that I had read somewhere, is the depression caused by the feeling of “failing to reach their potential”.
The more he knows about himself, the better armed he is. He has to accept who he is before you can accept who he is.
The real truth appears to be, from what you describe, that he is an alcoholic. And I may be wrong, but I’m sure he is way beyond a social drinker. His ADHD may have contributed to his drinking, but this would have been something that began a long time ago. He is clearly asking you to accept him as he is, an alcoholic, who makes you anxious whenever you are with other people, and says things which make you upset.
If he can’t control his drinking, then things can only get worse. Treating the ADHD, without getting sober, doesn’t sound too promising to me, but others may feel differently.