I feel you. I'm a student and I've had a group of friends but I just don't feel it, I don't feel like I belong there cause that's too much. For a part, it's fun too but I don't get that much of a me time! Which is honestly needed most of the time! So chill girl, there are lots of people dealing with same issues and MORE POWER TO YOU!
It happens, try to take usual time outs wherein you try to only be with yourself. Some people need social disconnects quite often and that’s completely fine.