Are you saying that your endocrinologists have told you that you have brain damage, through a low carb diet @forge?
It would be helpful to have some evidence of their research papers.
I'd assume that they were confusing their carbs with their glucose? We don't need carbs for brain fodder but we do need a minimum amount of glucose, which our livers will provide if we're eating low carb - as I understand it.
Real ice cream starts with a custard of eggs and cream, warmed until it thickens.
Adding sugar is for people trying to make the same thing with less expensive ingredients, though apple pulp is a possibility - I have two apple trees in the garden which would provide gallons of the stuff so I try to use at least a small part of it.
If you need to make it sweeter try adding frozen berries or artificial sweetener.