He left me and no matter what I do, I still feel bad

It's been approximately two months that my boyfriend left me. I dont hate him for that or have any negative feelings towards him. In fact I understand his decision based on what I understand I did at the time. It is weird because we only dated for 3 months (so I was really not even supposed to feel this bad, maybe it was just something that didnt work out.) but I still feel awful. I cried everyday for basically a whole month and a bit more. I had/have this feeling that no matter what I do, I will only make things worse.

I'll try to explain what happened. In the beginning of course everything was great, we had great conversations, and we were very happy with each other. I felt quite differently about him as I felt about anyone else I've ever met (even as a friend as we were in the beginning). I felt caring, as if I could feel that all he needed was a hug and someone to hold him.

I never felt such level of caring before. I never felt like I wanted someone to be so happy and that I wanted to be the person that would make him happy. All I wanted was to hold him so tight that all of his broken pieces would put themselves back together again.

It was all great. Until he received some news from a uni that is 700km away. And maybe he would have to go there. After that I just started worrying so much. And got so fixated on the idea of not losing him that I ended up pushing him away, and saying a lot of things without thinking. I just feel so sorry wishing he could take me back.