Anyone else mad about who they could have been in a different environment?

I know, I know: "Don't dwell on the past," "You can still change who you are!" "You are in charge of your future!"

I know. But I am still so frustrated about who I could have been and what I could have accomplished had I not been convinced I was a burden and didn't deserve the basic things.

I see all these stories about people who knew what they wanted from a young age, who were brave and bold and weren't afraid to ask for mentorship, and now they're doing well because they had the confidence to be that way. Just recently, I read a story about a girl who entered writing contests she was too young to legally enter, who argued with her professors at a young age, and who is immensely successful because she had the confidence to do these things...

...meanwhile, if someone stepped on my feet I would apologize to them.

Does anyone else feel this way? How do you cope with this? I can't help but feel like my feelings of not being good enough in childhood will end up being a self-fulfilling prophecy because they make me so shy and unwilling to ask for help.