What...break up... And now she loves me again?

Well the story begings like this that my ex-girlfriend now she cheated on me with my best friend and nabour and I forgave hear for cheating on me with him. Now 3 days later she tells me she has feelings for him and she told me she’s never going to see him again. Today 4 days later she just told me she loves him more than me and broke up… Well the problem now is that she’s saying that she actually really loves me and just said that because she felt really guilty for what she had done and never actually meant it that she love the other guy, it was just all because she wanted me to break up with her because she actually felt that guilty and wanted to get away with her guilt and told me that. She’s also wants to know how she can prove her self that she actually loves me… Now what should I do about this? People are telling me that shes a you know bitc… And never trust her again for what she has done… I need help I really dont know what to do I really love her but I dont know if I can trust her… What should I do pls help me