No Longer Pleasurable

I have this habit for a few months of eating french toast in a cafe every morning. I look forward to it as one of the highlights of my day.
As I built myself a protocol that excludes french toasts, I had failed at processing the urges over the last few days.
What I don’t understand is this: I have an urge to go ‘just one more day’ as my brain phrases it and I go and order it. By the third bite I start to feel a bit sick in my stomach, bloated, truly unwell. But I finish the plate.
The entire experience was pleasurable for three bites and then not at all.
Why would my brain encourage me to eat something that makes me sick physically? If that was back in the days a rotten fruit my brain would remind me not to get anywhere near it..,