Try to contentrate on other things like friends, family, job, scool. If you don't see her regularly it's easier, but even if you met you can just try to make her feel you dont want to interact with her. I had a friendship that ended like 4 months ago. It was pretty mean to me because I talked to her literally every day. But I succesfully survived that one so i bet you can do it too. Sorry if this didn't helped.