Your best bet is moving on, looking good, being fit and looking like a great catch.
Even though you aren't seeing anyone now, don't be afraid to go out on dates and meet new people.
In every sense of the way, when you are around her ACT like you've moved on and are no longer an option for her, but don't be cruel or nasty about it.
Just be matter of fact about it.
Detach from her and if down the line she wants you back, she can work her a** off for it, but don't wait for her.
Get online and set up a profile.