I started getting angry at the words at one point in time.
You used the word sincerity in your post. That got really confusing for me. My hubby I think did mean what he said often....but his behavior could not match up to his words.
My hubby stated once (re: alcohol and affair). "I don't know when my word became so untrustworthy." He was incredibly sincere at that moment, and I just looked at him dumbfounded (I think it was a revelation for him). I have had so many emotions about it over the course of healing. It became a revelation for me. His behavior had consistently been insincere for years. His words where what he thought I wanted to hear.
That sincerity piece was really hard for me. I hope you can be easy on yourself about it.