I feel bad responding to a very beautiful, poetically written ventpost with prosaic advice, but I'm going to say this:
Resilience is a skill. Being able to shrug things off is a skill. being able to curb your immediate emotional reaction to something, being able to process your feelings in a way that means you can do something with them rather than being consumed by them, and being able to soothe yourself til you can sit down and process those feelings? that's a skill.
It is a skill that you can learn, and it is a skill you can get better at.
unfortunately, like foreign languages, it is a skill that is easier to learn when you are a child. just like you learn a native language from the people around you, you learn from the people around you- usually your parents/guardians- how to react to things that hurt in the moment, how to soothe yourself until you can process them, and how to process them until they don't hurt anymore.
if you're highly reactive, the odds are good that, for whatever reason, you never learnt resilience as a kid. The people who were supposed to teach you how to handle the weight of the world didn't, or couldn't, or wouldn't.
if you try to learn this skill as an adult, you have to convince your brain to do things that it was never taught how to do, after it thinks it does not need to learn this anymore. in the same way that it's goddamn hard for a native adult English speaker to sit down and learn how to speak Russian like a native, if you never learnt how to be resilient when you were a kid? it's going to be a bitch to pick it up.
if you learnt "the world is scary and out to get you and there's nothing you can do about it, you WILL feel EVERYTHING ALL THE TIME" (or "showing your feelings in the moment will get you hurt, you need to bottle everything up until the bottle breaks and you get hurt with fifteen years of feelings at once", or "minor inconveniences are the prelude to The Adult In Your House Who Shouts coming down on you like a load of bricks, if things aren't going perfectly then you're about to suffer", or any number of other things), trying to learn that the world doesn't work like that any more is hard and it hurts. Unless you're really good at figuring out what you're thinking and why, you will probably need to get professional help.
You're not from the wrong planet. You just never learnt something that's as basic a part of being a human as talking or counting. You were failed, and it's cruel and unjust that no one helped you pick up the slack.
....But adults learn Russian every day. Adults teach themselves Russian every day.
You can learn how to do this. You can learn how to get better at dealing with the stuff that hurts you. You can become more resilient and less reactive.
you are not doomed to get hit by everything that happens to you like it's a truck forever.
