I feel disconnected from my friends

So for a little context, I go to a small private school. I started in middle school but most of the kids have known each other since elementary. I have a good amount of people I’d consider my friends but I have this weird feeling of being disconnected. For example I’m almost never contacted unless I contact them first. Everyone is friendly when I’m with them, wether at school or at a related event. However I can’t shake the feeling that I only entertain them and am not seen as a genuine friend. I get even more paranoid when I see them at or hear them talk about events I was never told about. I am a very self aware person so I know it’s not a situation where they have me around to laugh at me, but I still feel like there’s a divide happening that I don’t understand. The whole situation has made me very paranoid and I’m not sure what to do about it. I can’t exactly find new people to hang out with either considering how small the school is.