I broke my best friends heart and it feels awful

Me and my friend have been talking consistently for the past few years. We started as online friends because he lives in another part of the country but this past summer he came and stayed with me and my parents for 2 weeks and from then to now we've become a lot closer.

We've ran into problems a bunch of times where I would feel like he was being clingy and I would pull away (over text) and then he would get kind of distraught or hurt and then we would talk about it and get through it. Or another thing that would happen was I would get in a bad mood, I would get irritable and take that out on him (I know doing that is wrong, I'm not proud of those moments). Even still, we would talk about it and get through it. Eventually we reached a point where I felt a lot closer to him and like I could even see myself dating him in the future and he said he wanted to as well. But then recently I stopped and reassessed whether I thought a relationship with him would work and I decided I didn't think it would. I don't know if that's even true or not because I struggle with my sense of self and knowing what I actually want but that's the decision I came to.... So I told him that and now he says he doesn't know what to do and that I hurt more than ever and I feel horrible. Idk what I'm doing.

I think he's the closest friend I've ever had and yet I keep hurting him.. I don't want to hurt him but it just keeps happening. I don't know what to do.