I realize I still don't know myself well enough...

For example, when deploying a strategy, the data shows a long-term maximum drawdown of 30%, but once it actually runs, an 8% drawdown makes me start doubting the strategy, always thinking if I made a mistake somewhere...
I find that my suspicious personality really affects my ability to make money, always doubting everything, and eventually even doubting myself...
Is there any good way to deal with this?