Broke up with bf yesterday, sad/lonely and worried about him

TLDR: broke up with boyfriend because we're not compatible, and both have growing to do. Sad because I'm alone, and worried about how hes reacting to being alone again.

Sorry this is long :/

Broke up with my bf yesterday because we honestly just weren't compatible longterm. I do really care about him, so breaking up sucked, but I didnt want to be in a relationship that I couldn't see a future in. He was really clingy, always complimented my looks, "liked hearing me talk" but he never really showed me that he knew anything about me or my interests. I wanted us to work but we have some pretty significant key differences that we couldn't seem to work through, and hes hasn't seemed to really develop the skills required to be in a functional relationship (or to be a functionally regulated person tbh). I delayed breaking up with him for so long because it made me nauseous to think of how he'd react, when I did, it went okay all things considered, but now im stuck feeling sad about being alone again. Like I said, he isnt really emotionally regulated and he was always at 110% attachment to me all the time (I literally never got a break), so I'm worried about him now that I'm not there to regulate and reassure him, especially now, since going through a breakup is hard enough as is. I know it was for the best, me and him considered (he has growing to do, and so do I), but I cant help but feel like I'm back at square one and I hate that I'm using all my energy to worry about someone ive chosen to not be in my life :(