Ex girlfriend issues. Some advice appreciated.?

My ex broke up with me about a month ago. I'm still madly in love with her. She is really everything I've ever wanted in a girl. I respected her, was nice, we got along well, and for the most part were happy, until she had some stress due to a new job and family, and she broke up with me.

I just learned over facebook that she is now going out with another guy, and I'm really upset over it. I really want to be with her still, but I know that its not going to happen. I'm just wondering what I should do. She wasn't just my girlfriend, but she was my best friend since we started going out. Really, it was insane how happy she made me.

I don't know whether I should try talking to her, and telling her how I feel just to get my thoughts and feelings out, or if I should ignore them and try to just shrug it all off, or what. I've got an obsessive personality, but I'm not pushy with her at all. I've given her lots of space since the break up. This just really does hurt a lot.

So should I try talking to her? Or should I just cut her out of my life completely without any contact?

Also, any advice on getting over her? I'm just really messed up right now, and don't know what to do.