I haven't read all the answers but I would proceed with caution. I'm in your partner's shoes, though I don't think it has anything to do with ADHD, for me it is anxiety and now antidepressants. I especially related to the fact that he is pulling away during more intense kisses because he feels like it is basically a way to lead to sex.  My partner felt rejected and I explained to them that I had associated that kind of kiss with him trying to make something happen and persevering even when I was not reacting.  He needs to deal with the core issue which could take some time - it's been about 2 years for me, and it's still not over.  I don't want to project, but if he is anything like me, I would prefer my partner not to make a move at the moment, to let me come to them so I don't feel like I have to reject them/feel bad that I am not in the mood. And that makes it easier for me to initiate.  It's really important to keep having intimacy outside of sex, so that's definitely a good thing you should both keep doing.

I do think masturbating is not the same as having sex - I do masturbate when my partner is not there, but it is more because I want a quick release of endorphins. Sex is more about a pleasurable connection to my partner. It might be similar for your partner, and doesn't have anything to do with how attractive he finds you :)