Idk if it has to do with the prefrontal cortex developing but I was also doing a ton of meditation to adjust my thinking at the time, but maybe 27 yrs old, my focus became me, not others. You literally decide what you feel!! You are in control. You just have to start steering your own brain. I’d definitely say meditate everyday. On insight timer they have meditations specifically for seeking validation and emotional codependency.
I’ve heard that The Courage to be Disliked is a game changing book for this!
First, how old are you? Second, someone will always get more happy birthdays than you, and there are others that get no happy birthdays at all. we can’t base our happiness over what someone else has.