If you blame yourself for every loss, own your wins with the same energy.

Plenty of people run an accounting system where the losses are theirs and the wins belonged to luck, the team, or an easy opponent. That is not humility, it is an unbalanced ledger, and it keeps the total negative no matter what happens. If your mistakes count as evidence about you, your good decisions have to count as well. The standard cannot only apply in one direction.

Next time something goes well, say what you did that caused it, out loud or on paper. Be as specific as you are when listing your errors. The awkwardness you feel is a decent measure of how lopsided the system has been.