When you see someone from your past that was the start of your depression

So this is kind of a long story and I'm not entirely sure if I should be posting it here or in another forum but let's see if anyone else can help me sort out my feelings:

When I was young (elementary school age) I was bullied a lot...and by a lot I mean every day from ages 4-9. It was never anything physical but it was more emotional, manipulative, and verbal bullying and back then that wasn't actually considered "real" bullying. It also didn't help that the girls who bullied me were my supposed "friends" who made it their job to crush my self esteem to a point that at 9 years old I wanted to commit suicide. And despite reaching that breaking point, everyone thought that it was my fault or that I deserved it and I was the troublesome kid (minus I guess my mom who was the only person who understood that those girls were freaking lying psychopaths), because they were smaller and tinier than I was (thank you massive growth spurt that to this day I feel insecure about my slightly above average height) and better at lying. Despite moving at the age of 10 to a new state, my depression, anxiety, and feelings of sucide ideation followed me until I finally got help this year and started medication at 22 years old. That's a really long time to screw someone up in the head and make them feel worthless.

So why do I bring it up now? Well, today I'm doing better-my life is full of friends, family, school, work, extracurriculars, and a lot of stress but nothing that I can't handle (maybe...). So today my dad brought out the old family album to show my sister what I looked like when I was her age and you know those class pictures which has everyones names and faces on it? Well I saw the girls who tormented me. And naturally because I became curious-I looked them up online. So I saw their Facebooks, Instagrams, Twitter profiles, etc and they are doing perfectly fine in their life. They are pretty, popular, and driven which I guess bothered me for a reason. I mean while I do have friends and other wonderful things in life, I guess it bothered me that they were in a good space too despite screwing up my life so much. And while I am a really down to earth person- or at least I try my very best to be, these girls are like showing off everything and getting so much positive attention for it. It's not that I'm jealous or anything its just that I feel bad about myself again for a reason....and I'm trying to sort out my feelings but I don't know why