I've done the break up after 18 month relationship. It's not an easy thing to do but you do manage it. It took me about 2-3 months and now I'm personally fine!
The rebound idea although very tempting doesn't really help as it's not fair on the other person and in the end you just offset your misery on to someone else. What I found successful is that I went out loads and met new people.
You have a natural desire to have an "equilibrium" of friends. For me this seemed to be about 5 really close friends and then a further 10 outside of that who I'd still consider friends. If you've just split up you've lost a "real close friend" in order for you to be happy you need to fill that gap with someone else. It doesn't have to be another girl but that's why going out and finding new people will help take your mind off it as you can fill the void.
I'd definately avoid contacting her. The fact you want to "contact" again suggests to me that you think that maybe "it still could work". It may well do, but you can leave it 6 months and if it was going to work tomorrow it will also work in 6 months time. Just don't get into an endless cycle of getting back together and breaking up.
Finally, the best of luck from me but you will get over it. As the cliche goes "it takes time".