You need to socialize more.
Either join a club, sport, or some sort of organization. I row for my university and am in a fraternity, now I don't know if you categorize those as "those clubs and stuff"... but you've got to get out.
Find a new clique to hang out with while maintaining your current ones. Only a few people in the rowing club know I'm out, while the majority of my fraternity knows.
From this point, you'll find a guy. at a party, in your club, etc... or just through friends.
If you like guys 23-25, then talk to a professor about joining his research team (if they do it depending on your major) and you'll find plenty of good looking guys. Some gay (in mine there's 2, but no...
, I wouldn't go for them. Lol)
You say you're 19, but that would never toss a club opportunity out of the window. It's true some are only 21+, but I heard of a gay club down here that's 18+. Then again, not really a gay club type of person.