How do you get over some one you've had feelings for for 15 years?

Crazy as it may sound, at the age of 20, I'm struggling with feelings I've had, in some capacity or another, for a girl, for 3/4 of my life. Some of you may familiar with my story, already; to sum it up, we haven't seen each other in a few years, and a year ago, I got back in touch with her via MySpace, and tried to take things from there. Things seemed to be going alright, but I kinda hit some road bumps along the way, and things haven't been the same since. Exactly seven days ago, I wrote her a message, a "last ditch effort", if you will, in which I just put everything out there, was honest, sincere, and straightforward, and ended it by basically asking her out.

A week later, and still no response. I suppose there's still a chance that she'll write back (it has taken her a while to respond to my messages in the past, every now and then), especially if she's really taken aback by that message I sent her. But as of right now, I'm guessing things aren't looking good, in terms of my chances with her. :/

So... I don't know where to go from here. It's rough, knowing that this is just... over. A small part of me feels a bit relieved. But when I really think about it, it just feels like a big part of me is missing. I can't stop thinking about how I'll never see her again, how in 5-10 years she'll probably get married and be starting a family (as crazy as that may be to think about), with some other guy, no less. For some reason, it hit me really hard last night, and I couldn't even really get a lot of sleep. x_x

I have a hard time letting go especially because, as you can probably guess, I haven't exactly had any past relationships (or even dates, for that matter). This girl, to me, was like, my last hope of finding some one. I'm so out of the social loop (no real friends besides "work" friends), and I'm too introverted to go out of my way to put myself in social situations or meet new people. Now I feel so hopeless, that I'm so set in my ways, that I'm never going to find some one. And I don't want that to be my life; I don't want to be that guy that never gets married, or has a family of his own. But I'm... stuck.

Sorry this topic got so long... Just needed to vent a bit, I guess.

Dude... your 20... It's a little early to be having a Life Crisis.

Did you ever MEET this girl in person before you dropped the "Date" bomb? I'm thinking you put her off by coming on too strong.

Did i mention your only 20? Quit worrying about growing up alone and with no family. Now in 10 or 15 MORE years, if your still worried. Then by ALL means, come back and ask us about it.

Until then? Just go out, have fun, meet people. The easiest way to do this is to just have common ground. And if you do stuff you like and meet people that are doing the same thing, BOOM Common Ground.

Quit worrying so much... Your young.

Of course you are having a hard time letting go... this dream life of yours has been central to your identity for far too long, and now you are faced with grieving the loss of your fantasy. Go ahead and mourn the loss for a little while, but then drop it. This girl was never yours, and you had an inappropriate amount of emotional attachment to your fantasy. If you can't move on in a couple of months, I suggest you get some therapy. Males who have clung to imaginary relationships with girls often end up bitter and ugly when the reality hits them, and that bitterness screws up their chances of meeting a new girl.