[xenophanes]

> Some people say this is what entering adulthood's like, but everyone around me seems to be perfectly fine.

Are you broadcasting not being fine to anyone but your closest friends? No? Then it means nothing that they aren't either.

Anyway, learn philosophy. You're asking philosophical questions. Most philosophy is bad and makes no sense. However, good philosophy is very useful. See Karl Popper. And you might try www.fallibleideas.com