Upset & heartbroken

Ok I’m not going to go on a long story here but my fiancé cheated on me...... 6x with the same girl. Now he went on this long apology and convinced me he messed up & that he truly loves me and wants to be with me. I love him more than anything but.... I have a hard time believing 6x is a mistake..? And with the same girl?? Also these cheating incidents have all been since we got engaged

I’m torn & heartbroken I love him and want to be with him but this is my dilemma. Advice??