hey Dr. i just found your account and i am happy to say that i started a similar challenge for myself this october. eat carnivore + dairy. no caffeine. no alcohol ( i was drinking minimally but still) and no marijuana/drugs. 

i have had similar symptoms to you. headaches/migraines fatigue. they suck when they come, but after i feel really good. my babies kept me up all last night and i would have loved coffee today, but resisted! 

best of luck doc.