What happened to my self esteem and happiness?

Hallo there!

So I have been together with my boyfriend for 9 months. In the relationship I was kinda happy but at times deeply unhappy. I really loved him and still do, but I decided to break up with him because he moved to another country and I didn‘t want a long distance relationship. Now I really miss him but I know that there is a reason why we broke up and getting back together isn‘t a choice.

While I was together with him, my self-esteem detoriated extremely. Slowly at first and suddenly it was all gone. I was always a very confident person and self assured, but not any more. I cry sometimes at night and feel like a total failure. He never said anything wrong to me, he always was very kind, but still there always some kind of tention between us that I couldn‘t explain and that made me feel under pressure. He never really liked my so we only did things with his friends and I was really unhappy about it. He was always very confident as self-assured and he thought of himself as perfect (for me it looked like he did) and sometimes it felt that he loves himself more than me.

Now I am very upset, unhappy with my current situation and I don‘t really now what to do about it or how to feel better again.

Can you guys give me some advice? That would be so nice.

Many thanks in advance!