My Gf of 8 months felled in love with another guy, I'm going crazy.?

She always told me she really liked me, how she was happy to get to know me, etc, now she found another guy at some bar 2 months ago, she told me that at first they were just friends, but she started felling in love with him, she even told me she never felt the same for another person before, and I should not get mad at her cuz she doens't have control of her feelings, to me that's the stupiest thing I ever heard! she wants me to still be friends, but I can't every time I see her I will remember I had feelings for her, what can I do about this? thinking about dating another woman makes me crazy.