Hang in there and know you are not alone. I've been through breakups on both spectrums (Girls and guys - not that it actually matters) and I know how hard it is. Don't let yourself fall into depression (I let myself get into that trap, and it makes it even hrder to get out.
Acceptance is the first step, once you know that there really is no chance of reconciliation. Surround yourself with happy and supportive people. Keep busy.
I'm so sorry that you have to be going through this - hang in there!