They are only displaying their own weaknesses, but I feel for you.... I feel I have bridged a few relationships in family in my life, maybe not entirely healed, but one day my nephew wanted to sit with me and tell me how much he hated how his mother (my sister) talked about me, I cautioned him, you know you are talking about your mother, my sister, there are things that you can't unsay. It's common and sad siblings and family talk down to another in family. I wonder what my sister would have thought if her son was confiding in me his sensitivities, as he understood me as sensitive?
I'm sorry they treat u that way. U shouldn't hate urself, but just hate the way they make u feel about urself. U can't control how others treat u, but u can control them having access to ur life and being allowed to make u have self doubt and self loathing. Remove urself from their reach. Choose to be around people who love and care about u.
You don’t have to believe a word that they say especially when it comes to gaslighting. Need to guard your tongue too….you live with yourself and shouldn’t hate yourself.