Why sm i so angry that i was diagnosed as an adult and not when i was younger

i was diagnosed at 29 with autism, i have reached the anger stage of acceptance, i am not sure why i am so angry i think it is because if i was diagnosed earlier i may of received the help i needed at school and people would of treated me differently instead of bullying me, i went my whole life being bullied for being different, i also have fibromyalgia now so that doesn't help, i struggle to make friends i just keep myself to myself and do my work, does anyone have any advice, how did you feel when you were diagnosed later on in life.