It's all a learning process. Do whatever you feel like doing. I learned the hard way that no contact is a good way to go. Even if you want to be back together with her, talking to her and bringing up the pain of the past while trying to heal won't get you anywhere. Just gives her more time to find somebody else.
I wouldn't guarentee that the next girl after will be better. The longer you are alone though, the greater that chance is. Being alone really gives you time to go over the relationship, where and why it went wrong, and nothing will tattoo that information into your head more than losing something that was really important.
The reason why it's important to get out and do things is that if she does ever decided to come back and see how you are doing (assuming you have no contacted in a while) is that you want to be ready for that (if you really care about her and want to be with her). Because you won't be able to fake being hurt and that's going to be a big turnoff, and will justify her decision in the first place.
I've was with a girl for officially eight months and she dumped me and had a new guy within two weeks to a month of that break up (although I did the begging, pleading, I've changed) and it made things much much worse. But that period of time is just not enough time to really reflect upon and understand what happened, she is just trying to erase you with somebody else and while she may seem happy she is comparing everything about this new guy to you. Sure it will be shiny and new and fun now, but when it gets old, who do you think she will be thinking about then?
It's not a promise but it's just very unlikely if it makes you feel any better. You and her are done, there is nothing you can really do to bring her back. You can't focus on getting her back, but you can focus on doing things that make you happy. And that will increase your chances.
I haven't talked to her in over a month, and haven't seen her in a month, but I think I'll be sending her family a Christmas card. I care about her family and it makes me happy, regardless of what she will think of it. Is that wrong?
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.