I've been there too. It's too hard to move on, but you definitely should. Don't be emotionally attached to her or else you'll be feeling bad all the time, I've cut my arms 3 times all because I was feeling depressed by her.
But then later on, I was able to meet more people and suddenly, I met one girl who she fell in love with me, and then we keep talking like all the days and I wasn't depressed by anything, she made me happy and then I asked her out and here we are.
At that time when I couldn't move on, I heard a quote: "There are plenty of fish in the sea" and I couldn't get it at that moment, but I now can say that it's true and you should definitely move on.
Sorry for my english.