She Told Me She's A Virgin But She Has Been Sleeping With Our Neighbours

UNEDITED:

I really need help to deal with this betrayal I'm facing. I am a 26-year-old man and my girlfriend is 23. We both attend OOU and we stay in an apartment off campus. She seemed to be a lovely girl. She cooked for me, took care of me and was always there for me. We have not been Being Intimate throughout our
relationship because she told me she was a virgin. Although I was tempted to go out and sleep with someone else, I resisted because I felt she was a good woman and does not deserve it. I have heard rumors previously about her having something to do with some guys in the area, I refused to believe because I simply trusted her. One day, she told me she was gong to Lagos to see her family. I saw her off to the bus stop and went for lectures. When I got back from classes. I needed to borrow some
books for upcoming exams. I went to a friend who then told me to go ask another classmate who lives close. When I got there and knocked, the door opened and it was my girl standing before me. Tying a towel. I can't even describe the shock I felt at that point. I went back to my room in a daze and
just sat quietly. Eventually she came in and she started pleading. I remembered all the rumors I've heard and I made her tell me everything. It was then she told me the truth, about a few guys in the area she had
slept with. She claims she did not mean to lie to me. That she only wanted to impress me and that is why she lied that she was a virgin. She also says she didn't expect to fall in love with me and when she did, she did not know how to tell the truth. She told me she tried to stop being with the other guys
but she could not. Since that day, I have moved out of the apartment we shared. It's been about 2 months and I can't even get over the betrayal. I feel like I have been played for a fool. She has been begging me to forgive and take her back. I don't just want to let her go, I want to come up with a way that she will feel the pain she inflicted on me. I want revenge and I don't think I will be okay if I don't pay her back.
Please advise.