You should never try to fit into society, because it's society that is sick. It's the pressure of this sickness that is forcing you to go against your own personality. You should turn the eye inward, not outward. When you know yourself, discover yourself, you'll realize that there is nothing wrong with you. The problem is the juxtaposition of your feelings of trying to fit in colliding with your feelings of being yourself. I know this, because I went through the very same thing when I was in my early 20's. I almost went to see a psychologist about it. But there isn't anything wrong with me. I accepted that.
Yes, you're not a teenager right now, but you are still maturing. Men mature all their lives. (you are a Man right?) Watch what happens when you turn 30. You'll realize how immature you were for that 20 something decade. Your true personality will start to solidify itself later on. For me, it was 31 when I noticed that I didn't care about society anymore. What's more important? How many friends you have on facebook or happiness? I'm projecting here, as I am not saying you care about that stuff, but a lot of people do; and they shouldn't. Technology has further advanced this sickness that is going on. The only healthy thing to do is to get back to things our ancestors knew to be healthy. Diet, exercise, meditation. etc.
I think about how lucky you are though, technology is a double edged sword; can be used for good/evil. Luckily you have a community here of a vast array of people and their experiences to request advice from. I didn't have that.
Lastly, do something every single day, to further and better your position. Even if its only doing 10 pushups. Do 11 the next day. Do something more, each and every day. Drink less, etc.