I'm mostly the same way, though I've never even been friends with a girl.
I want to be with someone, to feel what love and romance and all that is really like, but then I look around at college or work and despair. Sure, there are girls there, and I'm sure more than a few fof them would be considered hot by most guys, but I jut feel nothing.
Doesn't matter who the girl is, what she looks like, or how she acts. Nothing.
There's no urge compelling me to get close to any of them, no drive to start up a conversation, even. Hell, even if I'm sitting behind a girl in class and she leans forward, causing her underwear to ride up out of her jeans in the back, there's not even the faintest stirring of activity down below. I can't even get sexually excited by girls.
I know I'm not gay. I once followed the lines of reasoning expressed by some in this thread and concluded that if I am not attracted to girls, I must be attracted to men. Suffice it to say, that reasoning didn't apply in my case. I will never again look at gay porn.
But I can't look at porn of real girls, either. It just doesn't DO anything for me. The only porn that's ever had any effect on me is hentai. The only girls I've ever felt attracted to are creations of ink and paint (or pixels and phosphors), not flesh and blood. And that sort of attraction, obviously, will never lead to the love or romance that I yearn for. But it does help ease the pain, if only temporarily. It's still possible to feel lonely even when cuddling up to an anime girl body pillow, believe me.
So, tl;dr -- I want to be in a relationship, but the only girls I'm attracted to are fictional. The contradiction here is somewhat obvious, but the only solution appears to be an epic orz of hopelessness and despair.