Where is the upset located? Is your upset inside someone else's body? No, it's inside your body.
All of your feelings are inside your own body. All of your thoughts are inside of yourself as well. All of your beliefs and judgements and opinions and viewpoints are all inside of you.
Ideas leave not their source.
The way you feel, these are your feelings. They're not someone else's feelings.
Part of your upset entails an energetic link between you and another person in which you experience your upset feelings as though they are 'connected to' the other person. Or in other words, your belief that your are upset "because of them" links your emotional reactions to the other person as though the two of you are joined together by it.
But if you can remember and own your own feelings - these feelings you're having are YOUR feelings, nobody else's. This is how YOU feel. You are the one having these feelings. These aren't anyone else's feelings. You are the one who is feeling upset. This is isn't outside your body and it's not in another person.
If you can get to that point and say that with any amount of conviction, you might be surprised that suddenly the seeming energetic 'link' or 'vulnerability' that you felt in relation to the other person, suddenly disappears. Much of the feeling that you had wrapped up in the perception of 'this is what they did to me', disappears also. You detach.
Your detachment allows you to come back to yourself. And then you can admit to yourself, and own for yourself, that how you are feeling, how you are reacting, what you are experiencing, is all YOURS. It's got nothing whatsoever to do with anyone else. There are NO CAUSES outside of you that have created this feeling or reaction or upset. That person didn't put it there. That person didn't make you feel this way.
YOU CHOSE to feel this way. These are your feelings, not theirs. These are your reactions, not theirs. These feelings are inside your own self and are a part of your own experience. That means they are under your 'control'. Or at the very least, under your ownership. They sure do not belong to anyone else. And if nobody else has created them in you, and you are detached from the other person knowing they did not cause these feelings, then you have to realize that you quite literally decided to have these feelings.
You chose to experience these feelings. You decided to have this reaction. You decided to create this energetic emotional response within yourself, when you thought you were stimulated by that other person. They didn't cause the reaction, they just acted as a neutral reflection. And in that reflection you saw something that brought up some feelings inside yourself that had NOTHING to do with the other person. They didn't make you feel this way, YOU decided to feel this way ABOUT what they appeared to do. So you chose your reaction and your experience and everything you feel.
You will find quite often that if you will claim ownership and responsibility for all of your own experience, in this way, is not only drops and disarms the ego perception of your experience being 'caused by' someone outside of you, it also correctly identifies that YOU are in a position of responsibility, meaning you are NOT A VICTIM, and therefore you are FREE of a sense of victimhood and all perceptions relating to it. This sets you free as well. And you will find if you do this - take back your power and reclaim ownership of responsibility for EVERYTHING you are experiencing - you will often find these feelings suddenly transmute all by themselves and just dissolve and deflate and disappear into nothing. And in their place, is often a tremendous laughter.
Being unlocked from seeing yourself as victimized or caused by others is the key here. If you take full responsibility for everything then nobody can have allegedly been responsible FOR something happening to you. And when you believe others are responsible for stuff happening to you, for or against you, you basically are being irresponsible for your own life and are CLAIMING that someone else is responsible FOR YOUR LIFE, for you.
Nobody else is responsible for your life. Nobody else is responsible for owning your true identity. Nobody else is responsible for the feelings, reactions, emotions and expressions that you are experiencing. Nobody. There is nobody to shovel your 'Self' off onto. Nobody to claim they are supposed to be living your life FOR you, or waking you up FOR you, or changing to what you prefer FOR you. This is YOUR life, not theirs, that you are living. YOU are meant to be fully and completely and squarely in the clear awareness and ownership of WHO YOU ARE, in full responsibility and identification with and operating out of your True Self.
You are invulnerable when you stop believing in victimhood.