^good point about them wasting your time, and effort, etc.
Don't let them waste your time, effort, love, and life, especially AFTER they have broken up with you. It's nice to be emotional about it, and I know I was.... but the bottome line is, you start wasting your own time, and you have to remedy that.
Don;t listen to any sort of love songs for a while, and listen to postive, especially self enhancing songs. And find things that you like to do on your own - that helped me. These are all suggestions, of course. I'm no master at getting over love.
For me, I don't even know if I would want to. I've shared a lot of things with that person, and the only thing I didn't like was malicious thinking. We parted on great terms, so I guess that helps, though.
Anyhow.... just remember how great you are, and how great your love is, and think about how lucky she was to have it. It is rare for people to fall in love, and it is just as rare for someone to be loved.
It goes both ways.
I always think about the lucky person who I'll give all my love to someday. I know that sounds arrogant, but it will be a special thing. I'm not even talking about how lucky I'd have to be. But love is always something you can look forward to, I suppose.
I guess my advice is to focus on the positives of the present and future, rather than the negatives of the past. And the cycle of life involves loss, but the most important part of loss is moving on. Otherwise you stagnate, and... decay. But I know that can be difficult sometimes.
good luck