Does anyone else feel guilty or very depressed after accomplishing anything?

I was labeled as gifted growing up, part of it being I was the smartest kid in the classroom in a lot of my classes. That generally meant that no one really celebrated if I did well academically since it was expected. It was really only a celebration if someone beat me. So I never got used to celebrating what I did since it would just piss people off.
My mom would also usually claim my accomplishments as her own since she raised me and my success was due, in large part, to her.
So I got used to not getting a sense of accomplishment when I accomplished something.
- I feel that so hard.
  All that ended up happening was I'd learned not to bother trying. If I didn't try I'd still beat everyone else. Then real life started and it turns out the only lesson you needed to learn in school was to learn how to try.

I used to feel bad about reaching milestones and "succeeding at life" because I was mourning a friend who could not reach those milestones with me. Therapy helped a lot.
- Grief is a real motherfucker

I have a multiple friends who, whenever they find success, almost immediately feel guilty and apologize to anyone else involved. In every case, those friends come from backgrounds where they were surrounded by narcissists. The guilt and apologies are a programmed response because "friends" and family would always frame their success as someone else's, usually their own, loss. This is now the lens they see every success through.
Win at a game? Apologize to the people you beat. Interview well and be offered a new job? Feel guilty about the other applicants. Hell, go out for a meal with friends and your food comes first? "I'm so sorry, guys."
Narcissists have programmed these friends to believe that they are undeserving of success, or even good luck, and that they should apologize for existing. I do my best to reassure them when I can, "you earned this," or "you had nothing to do with this happening," but ultimately it's something they have to grapple with until they can figure out for themselves how to grow past that programming.
I have no idea if this applies to your situation, but it is a lens to consider.

This is interesting to me because in the moment after accomplishing something, I feel great about it. It's only after time has passed that I look back at that accomplishment and my collective accomplishments throughout life and think to myself "omg, I haven't done anything, I'm such a loser", when I have in fact done plenty of things. I have no idea where that thought process comes from. I am not afraid to succeed; I have had to work hard for some, but not all, of my accomplishments. Maybe it's a "comparing myself to others" thing?

What's the thought in your head that pops up next to your feelings in such a situation?
Mine is usually something along the line of "So that's it, huh? Doesn't feel so great after all".