Hey there 🙂
I just want to say, from the beginning, that I do completely understand your frustrations. That being said, however, your boyfriend’s behaviour is COMPLETELY in line with ADHD.
The whole ‘hyperfocus during the beginning of a relationship’ primarily occurs in ordinary relationships, not long-distance ones. There’s nothing WRONG with long-distance relationships, I’m not saying that at all, but they’re especially difficult for people with ADHD. The problem is the distance. The problem is having to remember to call or message regularly. The problem is having other things going on closer to home. ADHD people are kind of wired to focus on whatever is in front of them, to the exclusion of all else. If you were in the locality, he likely WOULD be lavishing all his attention on you (assuming that he IS interested, because what you’re describing COULD also be a lack of interest, but if he says he is, I’d take him at his word) because you’d be THERE. But bear in mind that this overly attentive state would only last, at best, a few months. He would seemingly start to pull away afterwards as other elements in his life came to the fore, and the relationship lost its novelty. It wouldn’t be that his feelings had changed, but the way he shows them would have.
But yeah, the symptoms you describe are completely typical, and should not be taken as signs of lack of interest AT FIRST GLANCE. They MAY be signs of that, if he actually ISN’T interested, but based just on those, you have no reason to think that he isn’t.