It might not be what you need to hear but it got me many years to literally teach myself not to give a shit about others which is probably not a good solution but it worked for me, even though I kinda became antisocial... I only have a few people around now which I really like and I keep taking things easier (I used to overthink everything and not sleep at night) Everything used to hurt me and now I became insensible somehow because otherwise it would've been impossible for me to live in the society. It's like a protection mechanism but it took years to became an asshole and first I had to fake it. (btw it's not like I'm a bad person, I just mind my business and I try not to get involved or affected by others, that's what I mean by asshole, I'm not mean to people, I just try to keep them away). Also I learnt to love myself because I used to put everyone before me. It was also a long process but it's worth it. If you need help, go ask for it, don't be ashamed. There's people who love you out there