Imposter syndrome is often a totally rational response to living in a world that constantly lets us know we're not allowed to decide what our own needs are, and we're not allowed to decide who we are.
We're supposed to stay where we're put, shut up and be grateful.
So when you step out of line, your inner child, that fierce and loyal guardian, speaks up to protect you. "be careful! People are going to judge you! Maybe it's safer to hide!"
When those feelings come up, give your inner guardian a compassionate hug, and boot those thoughts right out with the trash. Tell your guardian "it's OK, we're an adult now, it might not feel like it, but
we can cope with this stuff. We're allowed to make other people uncomfortable sometimes, we're allowed to show people who we really are."