The first thing that will probably happen is that you will go through a grieving process.
Your body's emotions will slowly put you in that mode.
What you need to do is to know how to handle it.
Emotions are part of the body's way of allowing you to handle each situation as it comes.
You feel anger, hurt, and resentment, lost and just totally bewildered.
Handle your break up in a sensible way don't go out drinking and being silly cause the only thing you will gain from that is a hangover, find someone to talk to.
Take deep breaths, every so often, so that you don't start to stress about the break up, don't try to contact your ex, find a close friend to vent your anger and disappointment to.
Go to the gym and do some very strenuous exercise and hopefully this will make you tired and stop you thinking about it.
Break ups seem to bring on a melancholy stage and thoughts of what you and your ex use to do together come to the surface.
The future is a place of the unknown and you don't know what might happen I mean who's to say that you might get back together, anything is possible.
You just need to give it time to settle and then think of what your next step will be in other words getting your house in order before taking the next step.
You could always think about why you broke up and change things so it does not happen again.
Just let the dust settle before making contact again.