Do i have something wrong with me?

When I was in 5th grade my mother dropped me off at my grandmothers house and never picked me back up. One year later my grandmother got custody of me. I have been diagnosed with PTSD, depression, and anxiety mostly because my parents were abusive. I was bullied all throughout elementary and middle school for being weird and quiet ( in middle school i was bullied for not liking/ wanting to date anyone, they thought i must be gay if i did not). So once i hit high school age i found out my mother had stage 4 cancer and she died. Then my grandmother got rid of my cat ( this cat was the only thing that i felt comfortable crying with). She then forced me to go to either a christian hugh school or another school i absultly would hate. Then when i got to 10th grade she started yelling at me and saying terrible things to me. She started this behavior once she met her great granddaughter for the first time.