adjacent advice: if you need more confidence, get a cool jacket or a haircut or something and think about how cool it makes you. this is loser advice, but we're all losers here. swallow your pride and roleplay as a cool guy and you'll become a cool guy.
it might help to think of yourself as a character designer and also yourself as a character, which is again kind of insane person advice, but this is an insane-person-for-insane-person audience blog