My boyfriend who is about to get married sleeps with a female netizen. Where should my heart go?

My boyfriend and I were college classmates. Since our senior year, we've been together for nearly five years. After graduation, we went to his hometown of Dongguan, Guangdong together, while I am from Wuhan. In a new place, I was not used to many things, so my boyfriend and I kept arguing. I wanted to leave but I couldn't bear to part with him. I always thought that the romance during student times was very precious. After several years of work, my boyfriend and I have gradually become stable in our careers, so we plan to get married by the end of this year...