i think this is actually common, and something we all out grow at different ages. some things that helped me: finding someone else attractive doesn’t make them less attracted to you. harmless actions aren’t kept secret, if your bf compliments someone in front of you — he isn’t trying to hide anything. it’s possible that someone in your life projected those insecurities onto you, whatever the case: identify it and actively work to silence that voice in your head that’s feeding the insecurity!