I call what you went through the last stages of keto flu. I have dealt with it on every prolonged (greater than 7 day fast) I have ever done, and I just went through it this past week doing rolling 72s (currently on cycle 3 of rolling 72s). Best way to adjust where you don’t suffer as much is to eat strict keto for a few weeks prior to the prolonged fast to get your body fully fat adapted, but I will say that in my experience I just pushed through those moments and felt better afterwards. For reference, I did a 50 day fast last year and really struggled with the symptoms you are describing around days 7-8, but then from day 9-10ish on all the way to 50 I felt totally fine, fantastic even. Don’t feel bad at all for listening to your body and not pushing through when you were obviously suffering, but I’m just here to tell you that I have dealt with that “adaptation” point in every LONG fast I’ve done, and it really feels awful. Keto going in WILL make it much easier though because your body will already be completely accustomed to burning fats for fuel.