The story you tell yourself shapes every relationship. Notice the inner narrator, separate facts from stories, and stop pre-rejecting people.
The idea
The person you talk to the most is you. If you're quietly convinced you're a fraud, it shows up everywhere: you under-ask, over-explain, read neutral faces as disapproval, and pre-reject people before they get a chance to know you. Most of these stories ("I'm not valuable," "I'm not likable," "they're too busy for me") aren't truthful accounts. At best they're creative reinterpretations of the facts. Usually they're made up. Some days I feel like a pack animal carrying luggage for the troll in my skull.
How to do it
Ask yourself what you believe about yourself that you'd never say out loud, the kind of thing you'd want to hit someone for saying to you.
On paper, answer three questions. What do I really think about the people I care about most? What do I think they think about me? What do I think about myself?
Look at the gaps. Where are you harder on yourself than you'd ever be on them? Where do you assume they see you in the worst possible way?
Sort each story: mostly true, creative license, or made up. The unkind ones are just stories, and you don't have to believe them.
Example
A few days before the world locked down in 2020, I was inside a prison in Nevada. Not as a guest of the state. I was with a group of entrepreneurs teaching business skills to incarcerated men. The real work turned out to be the stories they'd carried, some for decades, about who they were and what they deserved. I sat there recognizing a lot of those stories in myself.
Second Thought, First Action: You can't control the first fearful thought about reaching out. You own the second thought and the first action.
Gap vs. Gain: Beat impostor syndrome by listing what you've already accomplished instead of how far you have to go. Then send the email.
You're So Typical: Most people feel bad at staying in touch, including the people you've drifted from. Swap "I" for "most people" and reach out anyway.
Guilt Is OK, Shame Is Not: Guilt is feeling bad about what you did; shame is about who you are. Shame drives avoidance, so drop it and restart small.