Hi Jane
If he's that definite, then yes you should start trying to move on. You know what I always find helps after a break up? It's a cliche but get a new haircut. Really, it makes you feel good about yourself. Spoil yourself a little - buy a new jumper, a new lipstick, girly things like that. Watch silly movies with your girlfriends. Have a girls night out. You know what else helps? Pack away or throw away all those momentoes, the little gifts, the photos, all the rest of it. Delete his emails. Forget his phone number. You don't need all those reminders around you just now.
It's not easy, take it in baby steps and soon you'll start to feel better.
Take care.