I hate to go with Palumbo on this one but macadamia nut oil and other healthy fats are the way to go. It won't do much for the headaches but at least it's something else to focus on. Fats are usually neglected. I'm the worst. Preaching right out of my ass to be honest, but I've practiced what I've preached in the past and it is very important.
Going in and out of ketosis sucks. At least once you're there, you feel okay. Hold out for a couple weeks total. You'll feel ethereal. You ever wonder how all them brown mofos meditate and eat virtually nothing, but feel great? There's a reason for that. It almost feels like you're intoxicated. Weak as a kitten, but high as a kite.
I hate getting hypoglycemic because I have a migraine problem. But after that stage where you've lost your appetite and started shifting into ketosis, you strangely feel really good (as long as you don't have headaches). Just stick it out if you've already made the commitment. Bang back some ECA and take advantage of this hellfire. Incinerate the fat and then start doing small refeeds. Allow some trace carbs too, just not so many that you start shifting back into using carbs though.