Well, first off, is he diagnosed? Or self-diagnosed? Or has someone else suggested it?
If not formally diagnosed, I would want him to seek that. Not you doing it for him, but driven by him.
Secondly, what strategies is HE researching and putting in place to help him with your relationship and in life generally?
Being ND isn't about sitting there saying, this is the way I am, I get to isolate you, gaslight you and make you cry, and then wave the get out of jail card that I'm ND so it's YOU that needs to tolerate everything I do with a smile. He should be making efforts to make the relationship work for you.
Tbh it sounds like abuse to me.
And at the end of the day, intention isn't magic - if you're suffering in a relationship, you shouldn't be in it.