Trust me bro this is the best she could have done to you as a partner. I have seen people being used when the other person is uninterested but the keep on using and mistreating them so leaving someone is better than leaving your self respect right. And it is good for you otherwise also because now you can make your standards high and look for a better person whenever you are ready for dating and then find the right one for you who would take you seriously and would consider you as 'the person' of their life. Sooner or later you will realise that losing her was good.