The girl I love is a victim and is very promiscuous. Should i continue to pursue her?

I had a great 2 month relationship with a girl who i have fallen in love with. After a brief period of being in love I was excited to see where the relationship would lead. It seems that when feelings started to get real she confided in me that she is quite a promiscuous girl - and really pushed me away. Eventually she told me she was d years ago - her first ual interaction. She also had a father who was never around. I love this girl but she has told me how bad she is and how she loves to seduce guys and break them so she can control them. I am a nice guy type and really want to be there for her, but I'm really tired of being the fool. Last time she tried to have with me i rejected her and told her it was all or nothing - in or out...I'm totally whipped on this girl...anyone have a similar experience? do good guys win sometimes with girls who use their bodies for advancement and control? should i give up? I could be the man that could help her through the pain...