What do i do if she finds another guy?

my ex girlfriend finds another guy. I mean, idk what i would do...i love this girl with everything i am...she waiting to have sex till marriage, but even another guy holding her hand or kissing her drives me crazy....i told her i wait for her till the day i die, and even in heaven ill be chasing her. i dont want another girl, its been four months since she broke up with me. But ive changed for me and her, ive gotten a ring for her...im going to wait for her as long as it takes...but will she forget me if another guy enters the picture?