Let's see... my first break up was quite a mess. After almost 5 years of dating, I was thoroughly convinced that I was going to marry her once I graduated college. God had other plans, but that didn't change how bad it hurt. It may sound over-dramatic, but in the 6 months or so that it took me to really get past that relationship, I came to appreciate two things. First, what rejected love is like, which I think helped me kind of get into the mindset of God and humanities rejection of Him. Secondly, what separation from love feels like. I was a mess after being separated from a girl who I probably shouldn't have held on to for that long to being with. The bible describes hell in somewhat physical terms, but separation from love is much worse than that. I'd take physical pain any day over the pain from that break up.
I guess I've kind of gotten off topic now. It took me probably a couple of years to really move past that relationship. I did some foolish things, and (even though I didn't intend to) I went through a couple of very brief "relationships" long before I was really prepared to. Dating for a week or two, nothing really good came out of them. Although in that time there were a few friendships that grew and luckily didn't become more. Supporting friends can be great, but be careful with friends of the opposite gender; it's particularly easy to develop feelings for the ones that support you, especially when you're so vulnerable after a breakup.
If I had known how, I'm sure it would have been a time that leaning heavily on God could have saved a lot of pain.
Hope this helps.