Trying to suppress a thought hardly works.
Case: don’t think about a flower.
Point: I’m willing to wager you thought about a flower, if only for a flicker of a moment.
Suppressing actually just reinforces.
As an alternative strategy, try acceptance the next time you’re experiencing difficult thoughts with this phrase: “I’m noticing I’m having the thought…”
I notice I’m having the thought that I’m an imposter.
or I notice I’m having the thought that I’m angry.
Putting these 6 words in front of what you're experiencing can help you notice your thoughts rather than getting caught up in them (a technique called cognitive defusion.).
And in so noticing, being able to coexist and thrive with them.