How do I curb an overly competitive mindset?

I find myself feeling jealous of alot of people's achievements when I know I should be happy for them. And I don't understand why I feel like this to the point that I can feel it physically. It gets very toxic that I undermine my own achievements and wish to be as great as they are even when I've not done enough to even deserve recognition. I understand the amount of hardwork and dedication for them to reach to that point but even with all the logical explanations, I still feel this quiet anger and envy inside of me.

I want to be a better person. Feel free to leave down some advice, thanks.