Does anyone know quotes on how to not expect the worst or let 1 situation always put you down. ?

So this one boy put me through hell. But I need quotes like how I shouldn't blame all boys for one boy's actions. Or how I shouldn't compare all guys just cus of one boy who did me wrong. & how I shouldn't expect the worst now cus all I expect is wrong -doing thanks to this guy. But I'm not with him. I been ended things. I'm never going back. Please & thank you :)