This is true. Only change what you can control. Don't cry over past events, instead treat them as a life lesson so in the future you won't stumble again.

Regarding other people's opinions and behavior towards me, I always listen to other people's criticism. I don't treat them as toxic people, because sometimes they are more honest than close friends.

If I think what they're saying about me is true, then I'll change myself if it will make me a much better person (because that's the only thing that I can control, myself) and hope that someday, people will see the change in me, then I can start to change their opinion and behavior towards me.