I was (am) a shy guy with a pretty strong fear of rejection, to such an extent that I'd never make the first move. I was low on confidence and hated myself for it because I knew that it frustrated her at times, but she re-assured me that it was ok and that we could take our time. She constantly helped to boost my confidence, telling me she was attracted to my intelligence, telling me I'd make the perfect travel partner,inviting me to her parent's house, and so on. We had sex a couple of times, hung out a lot, and messaged each other every day - things seemed great, and I genuinely thought that I was going to have a relationship with my best friend.

Then over the summer, she dumped me for someone else. Nothing had changed between us, she just met someone she liked better. I demanded an honest answer from her and she was very apologetic, but explained that she'd never seen us as serious because I was too shy and seemed scared of her. She wanted us to stay friends but we'd only ever see each other in a group of friends, and not really talk to each other then. It was pretty obvious she'd just lost interest in me, and because it was still hurting me, one day I decided to cut her out of my life completely. Two years on and I'm still not over her. If any of it was ever genuine at all, I can't see how she would lost interest so suddenly and not even been curious to see what we could have been. And yet I don't think she was leading me on all that time just for the sake of it.

I keep getting the urge to get in touch with her because I never got the closure I needed, even though I already got the answers she was willing to give me, and so much time has passed that it is now completely irrelevant (she's been with a new boyfriend for more than a year, and seems happy). What can I do to stop caring?