Why am I messed up but not my brother

I grew up very spoiled, always got new things, 10+ American girl dolls, family vacations every summer. My parents bought me things instead emotionally validating me. My mom always yelled at me if i cried and would tell me to stop being dramatic, ignore me most of the time when i spoke to her, yell at me over small things if i accidentally made her mad, i remmeber her telling me i was annoying a lot, etc. My dad (and mom) were at work a lot and I only really had one real childhood friend who would choose to hangout with her other friends over me so i was alone most of the time. I was very painfully shy and still am in my 20s. I still feel like a child with no social skills. I feel so immature compared to others my age.

In first grade I didn’t talk to my teacher at all because I didn’t like her I don’t remember why but she called my parents to have a meeting thinking I was autistic and my mom went off on her. Turns out I was autistic and found out 3 years ago when I was diagnosed with a psychologist. I always felt there was something wrong with me but my life was seemingly perfect from the outside because I always had nice things. So I felt I was being crazy to “complain” about how I felt because how can I be depressed if I have all of these material expensive things and clothes. I remember thinking of suicide at age 10 and planned to kms on my 18th birthday. That was my life plan at 10. My parents never showed affection to me and my mom never told me she loved me growing up . I also had a narcissist grandma who was very mean to me and I would have to be dropped off at her house before school when my mom had work. I’d have full blown panic attacks and hyperventilate and vomit before going because of how mean she was to me. When this would happen my mom would get mad at me and yell at me and tell me I’m dramatic.

My mom would comment on my body as a child and call me fat and refer to me as muffin top instead of my name.i remember one time on vacation I bought popcorn and it was late and my mom yelled at me for eating it and told me I was going to be the size of a house. I became anorexic at 12 and have had every ed ever since and still struggle with it. I have never had a boyfriend because I believed as a teenager that it’s pointless and they “don’t actually love you they just want xyz” and I’m too avoidant to have one now. I lost a lot of my friends because I believed they secretly hate me and have trust issues with everyone even if they show me there’s no reason to have them.

I still feel so stuck at 23 and have no actual career because I am too quiet to persue the career I originally wanted because you need to be social to succeed in it. But what I don’t get is how this can be my childhood and adulthood while my brother turned out normal. He is successful and has a wife and house and a good career, did good in school. But I didn’t. I wasted years of my life in my childhood bedroom depressed and alone. I feel like a loser. I brought all of this up to my mom when i was drunk and she denied it and told me I was spoiled rotten growing up and got everything I wanted and that all of this never happened. She told me I was crazy and dreamt it. My dad didn’t believe me either or my brother. I asked my brother if he remembers and he said no…. :(