How do you overcome financial loss and other unfair dealings in life

Like things that have happened in past someone stole my money(ofcourse I knew that person) , people at my last job very weird to act as if they helping but in hindsight it was very different pic and people who mistreat you, who treat you unfair , jobs that treat you unfairly, all these thoughts when they do resurface do make me mad and more mad at myself for being so dumb to let such things happen to me, how do I overcome such unfairness I have dealt with, in different situations and I know these people still exists and even doing better in their lives. And I don’t want to be fake happy or fake positive about things and feelings it really sucks and I hate some people, I can’t do anything about anything I know it’s all in the past but I want to overcome such feelings forever they are hindrance in me able to live better life,