How do I get past apparently ‘minor setbacks’ to have better days and better mood for most part of my life?

I don’t know where else to post this but it’s a general discussion about life so I think it will fit. Life for most parts is going great. But I can’t seem to get past these tiny humps that sometimes hit my body like a lightening and I am just not in the mood anymore. I mean to say, I can’t help but notice everything as a whole experience, a deep experience, and when I do that, I end up seeing the flaws and it gets me. I try not to be bothered, yeah, and I am mature enough to understand nothing can be perfect and that I need to appreciate both good and bad things in life - but this is a very annoying habit of mine I can’t seem to get rid of.

Let me state examples. So when something bad happens in college, especially when someone criticises me (for some fault of mine) I can’t rub it off soon. It burns my heart like a paper, slowly devouring and stinging me. And it takes a very long time to go, unless of course there is a bigger blow, or a highly distracting event. (Which may be, for instance, a new crush on someone, or that I will have a whole fun day to party, or that I’m going on a vacation; stuff like that)

I know deep inside me that none of it matters. I am a badass girl after all. (lol) But it does not dominate my feelings. The thing that dominates me - is that small burn on my heart that keeps getting bigger.

I also understand probably I’m the one who’s feeding this burn. But I can’t help it. Sometimes this weird habit of mine makes me loose days. I fall into a slump. I don’t want that to happen and I want to have a stable state of being. I want to look past that burn and say to myself, it’s fine, not a big deal. Not just say, I actually want to feel it! Any insights about this would be appreciated.