used to struggle a lot with this, was definitely due in part to a lot of insecurity but also some diagnosed anxiety issues. medication helped for me with the latter, but the insecurity I def had to tackle as I got older.
one thing that helped me was framing interactions differently. with an insecure mindset, each interaction has the subconscious goal to have the other person like you. that’s a lot of pressure! of course that will make you nervous if you feel like you’re always being evaluated. truth is some people won’t like you, some people will really like you, but most folks that you only meet in passing aren’t really thinking deeper than the immediate interaction and will find you pleasant if you have basic manners and such. ultimately, though, it’s entirely out of your control how others will perceptive you!
instead, I found that interactions are best if you approach them with authenticity and curiosity. all you gotta do is be your true self, people will think what they may but at least you’re being perceived as you and not you trying to perform how you think will be best received. and people generally want to know the people they're around! you should bring that assumption and just let the other person know you. you don’t need to be funny or an expert story teller, getting to know someone can be rewarding in and of itself. and you’re worth knowing! internalizing that truth will develop confidence.
in turn, get to know them! over the course of a conversation, you can really learn a lot about someone by just asking questions as they come up. be curious! it’s not prying, people love talking about who they are (within reason obv). interactions are hard if you don’t have anything to go off of, and that will always be awkward. so your goal is just to get to know a bit about who the person you’re interacting with is, maybe you’ll find something that resonates and then the interaction will come so naturally.
ultimately, no one thinks about you more than yourself. and that’s not to say you’re insignificant, but most people are too busy thinking about themselves to think too hard about you. whatever little minor thing you did or said, or how you looked or acted, so much of that will not be scrutinized by someone else nearly to the point you’ll scrutinize it because you think they’re scrutinizing it. find some relief knowing that you’re not being microanalyzed by anything other than your own insecurity, and you can choose not to listen.