[blizkreeg]

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

Your foray into adulthood does not have to be like everyone else's and around the same time. Some of your friends may mature and go through this later in life. Some will face a stronger mid-life crisis, having never gone through something like this.

Here's the transition all males have to make, at one point or another in their life. Boy => Guy => Man.

What you feel now will certainly pass, and you will be all the more stronger, and a man with purpose because of these (20s) formative experiences.