Just Got Dumped. Broken-Hearted?

So, I got dumped at recess by the boy that I thought was the one I would be with for a much longer time. We've only been together for about 4 or 5 months, which was about as long as my last relationship was. I need help to deal with rejection again. I didn't do too well last time and even thought I didn't want to, I cried about every night for a couple months. I don't want that to happen again. Please help me!!!