I wonder whether there are some tools that alcoholics use that you could apply here, then? Can you put it in perspective? What is it that has actually happened?

1) You bought one brownie
2) You ate part of one brownie
3) You destroyed and discarded the remainder of one brownie

After this your head went into overdrive trying to make sense of it - when you know it is something you had decided not to do

Okay that's everything that happened. Now what are you planning on doing next?

Can you stock up on fruit and vegetables that you know you like so they are on hand when you want to eat something else?

What is it you need to do to move on?