coming back to a cheater

i had a relationship with a girl for 2 and half years ,until by chance I found out that she had been cheating on me with a guy whom she met in 2001 in Santa Barbara.It took me 2 weeks to put all pieces of puzzle together .To my suprise she also cheated on her previous boyfriend with the same boy .What makes me sad and kills me inside is that she was playing on both sides ,securing her intrests .I still think of her and to some extent love her ,but i know that i cant come back ( i wish so -she was my first real love and woman ).She did it ,and a im positive that she will do it again.Coming back to me ,part of my soul and trust in women has been broken and it will take a while to be restored