How do you deal with someone dumping you?

I recently gut dumped, then figured out i was being used. My ex-boyfriend was using me for one of my best friends, who dumped him last year! Well she's dating him now, and it kinda ruined our friendship. The best things to do is show your ex, and the person he used you for, than you don't need them. Show your ex that you're better than him and that you can live without him, that you can be happy in life without him by your side. If he comes back to you cuz another realtionship doesn't work out, do not go back. Always act happy and cheerful and laughy when he's around. You're better than your ex!!!