What to do if your girlfriend thinks you cheated on her but you did not?

If you have already had a conversation with her and it leads only to more arguments, try going to a marriage counselor.

Invite her to follow you, read your mail, do whatever it takes to make her realize maybe she is just projecting her own insecurities on to you. Volunteer to go to counseling if she wants to. If she has been cheated on in a previOS relationship, and you REALLY love her, eventually , she will get over this. Living with an insecure person is tiring and trying, but if your love is steadfast she will learn to trust you.