On the validity of instinct and feelings
"Your brain is lying to you" is a refrain often seen on social media accounts, usually ones that talk about anxiety, or anxiety-related issues. It's true, sometimes. Your brain lies about people not liking you, or your ability to do your job or your worth as a person.
It's useful to push back against these kind of thoughts, and question your brain's narrative. Often when we do this we realise this internal monologue isn't our words. They're somewhere else's - family, co-workers, teachers, from past relationships*. They're other people's judgement that we have internalised and made our own, strengthened by our up close view of our own failures.
This can be even more complex if you've experienced trauma. If you've experienced gaslighting or minimising of your feelings, you might second guess yourself by nature.
Experiences that can cause this can be varied, but here are some examples: