I stayed on the diet for over a year and its really depends on the particular person of how they body responds. whats funny is people try to follow cookie cutter diets but each body is differnet im learning. like you for example, you were already hypothyroid. I didnt go hypothyroid until my adrenals got sluggish and also because i didnt eat enough Iodine because my food allergies wouldnt let me eat anything at all. but to back to ketosis, i was in it for over year like i said and then i started have alot of back pain then neck pain(thyroid) with severe hair loss(scalp,eye lashes) and cold intolerance. but funny you had more energy. probably because you werent eating carbs which can cause high candida toxins which cause fatigue if your zinc/mag/molybdenum levels arent good. eating low carbs boost cortisol in the blood but over time that can eventually waste the adrenals which leads to hormone suppression(gland deactivation), thyroid dysfunction then finally immunity dysfunction. vitamin D is a great energy booster id say. Im currently at 40 nmol trying to get to 70nmol, maybe you should get your levels checked?