Well I haven't broken up with my girlfriend, but just imagining it I realise it would make you feel really upset and empty. I wouldn't know what to do with my time anymore!
I think this early it's inevitable that you'll be upset, and nothing that happens can make much difference e.g. making some friends. You just need a couple of weeks and you'll accept it. I'm not telling you to be anti-social as there's no point in friends, just don't become obsessed with that and dependant on it. Sounds like you need to learn to get through things on your own, like I did a while ago now.
Being single may actually aid depression. You'll be doing things for yourself, be less reliant on him, not feel bad any time you're apart from him etc... just try to draw on some positives like that and you may feel a bit better.
p.s. Can people not call her ex a dick etc, he has supported her and been with her for ages. If you can't respect his wishes it's you that's the dick, he could be far worse e.g. cheating on her as he wanted new experiences, at least he was honest and in the long run they'll both be better off for it then if he stayed with her despte being unhappy about being unable to try new things.