How to Stop Caring About How People Perceive Me?

Okay this sounds horrible but I'm 16F and it feels like my only motivation to reach for greater things in life is to spite people. It's so draining that the only thing on my mind is to "one up" friends who've made fun of/mock me for reasons such as not having a job or license, grades, appearance/weight, not doing drugs or drinking, virgin, etc. In result of that I've gotten a job (quit to focus on school), take my drivers test next week, maintained higher grades, and lost 20lbs (the last two I don't plan on doing at all lol). I find myself holding grudges for literal years and hoping the worst for people. I'm wondering if other people have went through caring way too much of how other people perceive you to the point it's always on your mind?

TL;DR: How do I focus on myself, stop holding grudges, and not have the weight on my shoulders of other's opinions about me?