Why I have anxiety and depression

My brothers would always bully me and tell me I will never amount to anything and just constantly harass me. I was afraid to go home from school because of what they would say to me. They'd always say that no one likes you and that no one will ever like you. Ever since then I've always been afraid of people not liking me so I'll do anything to make them like me and if I do something to make someone upset I'll tend to dwell on it for days, weeks and even months even though by then they've most likely forgotten about it. As well my self esteem has been absolutley destroyed. Sometimes I'll stand in the mirror picking out every single flaw of my body and accuntuate it to the point where it's the only thing I see. Even today after 7 years of torment by them and their tearful apologies I'm still broken by it and I just don't know how to recover.