When it's over. Nothing is over!
Why do you think people have relationships? Because it feels good to share things with another people. However when we do it for a long time, we usually forget some truths about life.
There is no such things as "the one", rare, luck, coincidence. The real thing that good relationships have is the hard work from the both sides.
We live in a very large world that have millions of people in it that you can love. Believe me there is another thousands who you can love and can love you.
Maybe there is very important high quality characteristic properties of the person who dumped you. Don't forget the most important thing for having a good relationship is caring about it, working for it, trusting it, (both sides must do it) nothing else... If your mate doesn't do it anymore, it is time for you to not care about it anymore.
Don't push someone to be with you, find someone wants to be with you.
Really find her! Don't just sit on that chair, read this post and do nothing. Go out there join activities, meet some new people have friends and find an another "the one" :)
The true happiness has nothing about finding a girl that will live with you till death, it is about working in things that make you proud of. It could be a relationship, a life dream, being master at something, improving yourself, quitting bad habits, making new goods...
Ps: care about the ones who cares about you IN THIS VERY MOMENT :)