Seriously man, and I say this with no ill-intent or judgment, you need a therapist. This is way too much for me, an internet stranger, to unpack. I go to therapy for chronic depression that I had long before I was diagnosed with cancer when the depression got worse. I often feel like the universe taunts me by giving me everything I've ever dreamed of and then slapping it out of my hands and pointing and laughing. I'm not blaming you for anything, but we all have time to grow and the ability to grow and change and not be the person we were raised to be with the limitations placed on us. I was sent to an extremely small private Baptist school where the only "friends" I had were the same 18 kids from kindergarten to middle school, and I was mostly bullied and ostracized by them. My mother was overbearingly Christian and lacked education herself and had trauma from losing her first children to being kidnapped by her ex-husband which led her to being overly controlling because she would panic about losing us the same way. My extended family was similar to yours, it sounds like as well. I am by no means conventionally attractive and have been overweight the majority of my life.
Our experiences and trauma don't define us. The pain and problems we suffered aren't what make us who we are unless we allow them to. That bitterness you hold for it all, that deep contempt for a world where you assume everyone is going to reject you or judge you before even giving them the chance to do so is a choice, even if it doesn't feel like one. I just try to let such judgments roll off my back, because they will always be there, there will always be someone else judging us or rejecting us. I learned that in high school when I found out there was some kid who hated me and thought I got all the attention from women because of one of my few friends who even had a boyfriend who wasn't me. It made no sense because she was just my friend and was dating someone else, and it just made me laugh, because it was so patently absurd.
The only blame I can lay at your feet is your unwillingness to be open to the opportunity for things to be different instead of crawling inside a shell of self-protection by rejecting others before they can reject you, and even then I can understand why your trauma makes that hard. It's been hard for me in similar ways, but I promise you life is easier if you don't do that. I promise that you don't have to reject everyone to protect yourself, and that you're doing yourself more harm and disservice by doing so than you would by being open to the opportunity for something good to happen for once.
What probably makes me the saddest is how much how you speak reminds me of my longest-lived relationship, and the one that troubles me the most about it ending, where she felt like no one would ever love her and people would always judge her for her mental health problems and she had endless panic about being abandoned. I spent so much time and energy trying to prove to her she was worth loving, and that she shouldn't let people's judgments impact her, and that I wasn't going to abandon her. You deserve someone who gives you that kind of effort and time as well, but if you don't allow someone giving you that kind of time and effort to allow yourself to grow and accept that things could be better, try to change your outlook, you will end up still bitter and blaming the world just like she does, which is what ultimately ended our relationship. I worry for her a lot still.