How do I get over my ex? Please help I'm heartvroken?

So I went out with this girl for three years we broke up and we stopped talking and we talk now as Frieda but she tells me how she never stopped loving me and I never stopped loving her. But today I found out through a friend that during the summer we broke up se gave a hand job to a kid she knows I hate. And apparently he just made her.. But no girl can't say no.. I'm just sitting here crying cuz how could she have love me when we broke up but she did that stuff. And I dont want to hear oh get over her get someone else. Move on