I let people walk all over me throughout my existence

The abusive treatment you got as a child from your adoptive family and in school was something you could not control and was not your fault. In this world there are good and bad people, that's just how it is. It's how you deal with them that defines the kind of person you are. Stand up for your rights because no one has the right to hurt you but don't break the law, you have to rise above it all and be the smart one in every situation . You must not let what they did to you affect your future, you are no longer their victim but a victor, because you will strive to be better and know you will never be like them.

Some people look away when someone is being bullied, or ganged up on, they don't want to be involved due to cowardice or lack of empathy.

Be your own best friend, do not indulge in self-sabotaging behavior, allow yourself to dream of a good future, and strive hard for it. Lastly, choose well the people who you want around you, people who shall contribute to your growth, success, and happiness. Good luck!😊