Sensitivity is not a bad thing; it's just part of who you are. Maybe you need ways to express your anger or pain that are more helpful to you than what you do currently? You are your own ultimate judge - no-one else, if you choose to be so, and if you live with integrity, are true to yourself, and are authentic with people you care about, what can these cruelties do to you? Nothing significant so long as you are happy with your own conduct. The kids that are bullying you are being cowardly. Maybe you should also look into assertiveness training as that can give you some skills to help deal with conflict and so ease the amount of abuse you're suffering.
Be true to you.
maybe it's time you had a really good cry. Holding it back is not a good idea.
I am the same... They have a joke about me in maths but when they talk about it want to run out crying. I think the answer is to not let things get you easily and have a joke back if you can.
Good Luck... Let me know how you get on
be proud of who you are!