“You know that song ” how sweet it is to be loved by you ”? I cry whenever I hear it beca asdfadsf ”

You know that song '' how sweet it is to be loved by you ''? I cry whenever I hear it because someone I love used to sing it to me.But he was dishonest and I was his 2nd girlfriend while he has another girl elsewhere . And ??? Left me. What should I do to left me.What should i do to move on?