Hey dude. We're kind of in similar situations - though you were with your girlfriend for much longer than I was (only 2.5 years for me). She was my first girlfriend as well, and one of only two girls I've been friends with. The other killed herself a couple of years ago, lol
Check out some of my recent threads, they might have useful ideas in them. My "how to win her back" one is a bit gay, but the others might be worth looking at.
I know how you feel about "wasting" the time... although it's not as simple as wasting it, I think you agree. It's that it's such a shame that foundation couldn't grow into something more.
I don't regret having lived how I lived so far, re: girls. I was 20 before I ever even kissed a girl, and I never had anything to do with them at school or anything. I had an amazing time with my last girlfriend and I'm not sad that it happened - just that it couldn't have continued.
Maybe I'll regret it when I'm older, but it won't make sense to. Yea I didn't live the usual young-man's life of ****ing lots of girls and partying, but then they didn't live the kind of life I did - and who's to say which is better? All I know is that if things hadn't been how they were, I wouldn't be the person I am today, and so I couldn't reasonably want to change my past.
How did you meet your last girlfriend, by the way? How did it get started?