I think you're calculating something wrong - to consume 600 grams of fat, you would have had to eat more than 20 slices of x-large PapaRoni pizza... I feel certain you didn't do THAT!.... Make sure you take the nutritional information from the column labelled "Total Fat" and NOT from "Fat Calories"...
Now, even if you did do something ridiculous like consume 21 slices of pizza in a sitting... there is only so much your body can absorb/assimilate at one time! It would be impossible to literally gain several pounds of fat as the result of one meal, no matter how over-the-top that meal was.
I can't imagine why you would think it could take days weeks or months to recover from a one-meal blunder! Just start fresh with your next meal, and you can reverse any actual "damage done" within a few days, tops.
Goal 1 - break 200 (46 pounds lost)**DONE**
Goal 2 - leave obesity behind (BMI 29.9, at 185#) **DONE**
Goal 3 - BMI = Normal (154# or less)
| current weight: 172.5