Mental termites are words or arguments that slowly chip away at your self-worth, hitting you exactly where it hurts. If your brain is getting mental termites from a relationship, you must be in a relationship with a narcissist.
Me looking in mirror - I can't even believe that he cheated on me and told me it was my fault because I had to work late. I improved his life in every possible way. Now all the bad memories are bringing me down like mental termites.