They probably feel like what interests them doesn't interest you. You are simply moving in a different direction in life. If you are not sure what they are into, but they don't even try to make you feel included, that is a major sign that something is wrong.
If you don't know if you did something to them or if there was any conflict at all, I think that you should try to talk to at least one of them to try to figure out what's wrong. If there is nothing wrong and you're still excluded, you should maybe try to make some new friends.
If you find it hard to make new friends here's some advice!
When you pursue hobbies and activities you enjoy, you have a good chance of meeting people with similar interests. So check out some local events. Each event is a chance to make a whole new room full of like-minded buddies.
2-.Set a goal.
It might sound superficial, but the next time you go to a party, tell yourself you want to leave with three new friends (or maybe even just one). That way, you’ll be more open to meeting people and starting in-depth conversations instead of just smiling at the person ahead of you in line for the bathroom.
If you're on the shyer side, you might be a little hesitant to invite people out. While it is a little scary at first, and there is some risk of rejection, it's fairly easy to get used to. It's not nearly as bad as asking someone on a date. :)
You're feeling bad because you don’t know why it's happening. If you decide your opinion of yourself is a priority, you'll be less sad. I mean, you didn't intentionally try to hurt any of them, right? You're a good person, right? If you were them, you wouldn't treat a friend like this, right? Give yourself credit where credit is due and find friends more like you. Change is a part of life and almost everyone gets through it ok.
You've got this!
Lots of love, Nicole