Backslides happen. The ILY is definitely one to avoid, but I freely gave compliments said nice things and verbally thanked my H for kind actions on his part during the D.
Although I did say nice things to my H, it was NOT in a pursuing manner. For one, I figured by being "nice" he might be more generous during the D, and also there would be less fighting which would be healthier for the kids. For me, the important thing was emotionally detaching so that I never expected anything back from him. I could be nice, but still entirely "let go." No reponse could hurt me (I didn't care what he thought or said about me), I was too busy creating a new life for me.
There is no arriving, ever. It is all a continual becoming.