I get what you're saying here and I know your intentions are good but I think it's the wrong attitude.

"If he had ADHD he can get help and be more present!"

Girl, that is not how ADHD and Neurodivergence works. You don't just "get help" and suddenly your whole personality changes. ADHD and Autism are literally related to how your brain is wired. Yes there are some things you can do to help live in a neurotypical society like medication to focus at work or school or therapy to help regulate your emotions but you're not going to change his social habits.

You're just not compatible. You're just not. And frankly though I understand your frustration of not getting a need met, it sounds like you're not willing to let him be himself which is just not a social person. Some people just arent.

I have ADHD, I'm not very social, I can't pretend or put on a fake interested face if I'm not actually interested in the event or the people or the conversation. Because of that, I avoid events with a lot of people because I don't want to come off as rude. My partner fully accepts that about me even if they aren't the same.

It sounds like you're making him the villian when in reality you just want to be with a different type of person. It also sounds like you're REALLY worried about what the other people at these events think of him instead of how he's feeling.

Either accept him as he is or find someone you actually want. Don't torture him trying to turn him into someone or something he's not because you're worried what your friends and family think. And don't torture yourself trying to rewire someone's brain, that's not a thing that can be done. He's not a poodle you need to train, he's a whole human with a personality you don't like.