He said he is gone for good and exploring his world. Sucks, but he did let go a long time ago, and should should you know. He had the advantage of being ready to leave the relationship, YOU did not.
What you should do is stop keeping hope alive by getting news about him, and have no contact whatsoever with him, so as not to keep old feelings alive, and intense. When you get dumped, for whatever reason, you disappear, regroup, rethink, and start doing your own thing, with family, friends, and activities that you enjoy. In this way you can allow time to heal, and recover from your shock, and disappointment, and that may take some time before you can fully understand what you have gone thru, given your ages, and length of time in each others lives.
I highly recommend you stay out of a relationship until you do recover, or you risk rebounding, as he did, and becoming dependent, sad, and insecure. Not fair making some one an emotional crutch, or tampon for your hurts, while you heal, and trying to replace the hole in your soul only makes things worse, NOT BETTER. Time makes things better, and the busier you are for yourself, the better it will get.
Sorry for your loss, but it will get better as you FINALLY let go!.