How To Put Back The Pieces After A Break-Up

It doesn't matter if you have been dumped, or someone dumped you, the hurt and grief are the same.  No matter who's fault the break-up is, both parties can be left with a broken heart.  And, not only will you feel the loss of your partner, this event will also open up old hurts from other unhealed relationships, and more importantly, old pain from your childhood will also surface."I hurt so bad, I can hardly breathe.", was the statement from a friend of mine describing her pain when she broke up with her boyfriend.  And, indeed the will to survive, and to carry on, are affected by this deep grief.
To help yourself deal with this pain, realize that the loss of any relationship regardless of how long it was whether for 2 weeks, 2 months, or 20 years, that this loss is real pain.
Give yourself time and permission to go through the stages of grief that come to you.  Your experience with this loss will roughly follow: denial, hurt, sadness, anger, and acceptance.  Each of these levels of the broken heart experiences are phases of healing.  Allow them to occur as they will.  This is how you will heal.
Remember Both Sides ...

The first thing you might think is, "I love them, and I can't live without them!"  You might remember the good things that you shared at this point.  Do yourself a favor.  Each time you remember something good, also remember what you didn't get in the relationship, and the bad things that they did as well.  If you only see the good, it will be re-creating them as perfect people, and make the loss seem even worse.
And, as painful as the situation might be for you remember to: FEEL YOUR FEELINGS AND ALLOW THEM TO BE.  This will help you to walk through the major part of your grief in a short time.  If you keep stuffing your pain, you will carry it forever until you release it.  Let the sadness, hurt, pain, and anger wash over you.  Let it be, and it will dissipate that much faster.
When the break-up occurs call your best friends and ask for their support.  There isn't a person on the planet that doesn't have some understanding of what a broken heart feelings like.  Let your friends help you, care about you, and give you support.