You don't need to drink, smoke, have sex or party to have fun. That my be hard to realize, because at 19 and at college, I imagine that that is what most of your peers are into.
I agree with you, I generally don't like people, as most of them suck. However, human relationships are vital in life. Whether it dating, or hanging out with some friends, it is needed by most people.
You know, I am antisocial and found at a time that I hated most people. A good friend, and wise man, made me look at it
this way; 'in order to hate others indiscriminately, you must be holding a lot of hate inside, how do you feel about yourself?'
Man, these are prime years in your life. I'd hate to see you spend them isolated. Get out and do and see things. Strengthen your mind as well as your body. Meet people, yeah, you won't like most of them, but you might find you like some of them. Break the routine, take the road less traveled.
I would also suggest the taking up of a martial art. This will contribute to the development of your body in many ways, and it will also be an outlet of socialization.
Like the above posts said, if you are happy, then do what makes you happy.
But you asked for an opinion, and with what limited information I have, this is my opinion and best advice. Wolbarret, take care of yourself.