She cheated......... LDR?

Ok right so i was in a Long distance relationship with this girl. I was going to give my life up to be with her. I gave up most of it already just to please her. 2 fridays ago she when to her friends house and met her friends boyfriend. Whom she talked to for a week then slept with him on friday.... I broke up with her in anger and rage.... I dont need the heartache. The reason i freaked like i did was because she didnt tell me the guy did! And i specifficly asked her if shes going to sleep with anyone tell me first please. And she broke that... Well now the trust has been broken. What would you suggest or do?