I have been in your shoes so many times... I wish I could tell you to just get over it - but I know that isn't easily done.
Can you pinpoint the REASON you let yourself eat the ice cream??
If you are not allowing yourself any treats all day - that could be the trigger!
I know I have to keep some WW ice cream bars or skinny cows in the freezer - and because they are so expensive I truly do only allow myself ONE per day!
So give yourself a break - perfection isn't all it's cracked up to be - and you CAN do this...
Congrats on turning 50 in November... the rest of your life is ahead of you