Well, I haven't talked about my attachment issues with him yet, I'm trying to solve those by myself for now. Not sure either, what to say.
I have repeatedly told him that I feel I cannot express myself, I am not me there, or just partially me, I feel detached from myself and anxious a lot of times. But my anxiety is an issue in my life now in general, so maybe it's no big surprise that I'm like that there.
I'm also having this huge fear that I don't want to get to the conclusion that I am too attached to him and then I should not go anymore - probably because I am too attached.
What has helped, to accept all this. The anxiety, the not being able to talk, the feeling like crap after. But that doesn't mean the situation should stay that way.
I know, it's hard, it's like impossible to accept feeling like crap because that would mean you don't feel like crap anymore

Also you mentioned about craving closeness as you don't have it right now in your life. That can really cause the expectations to go high and it's an impossible task because we know that he can't be that person we need in our lives and don't have. I have the same issue. But this realisation in itself could help, that we have the issue.