I mean this in the nicest possible way, but I think you need to talk to someone and try and gain a new perspective. People aren’t inherently mean, and generally aren’t thinking about much other than themselves. People do “chill” as they get older and realize a lot of things really don’t matter in the long run.
Go find a team sport or a hobby with other like-minded people and focus on building a community of friendship and support. Your life is too short to not spend it being happy.