My insulin resistance increases tenfold ever week or so

I honestly have no idea what to do, I live a pretty routine life, I work the same hours, get the same amount of exercise, stress is low, I eat keto so food is consistent, but every week or so I'll go from a 1:10 to 1:1 for a few days and I cannot figure it out. Like yesterday, I had ten carbs and some protein for dinner, had to spread out 17 units throughout the night and I still woke up high. Any ideas?