Back to keto

I've been on and off keto since 2018. First time went from 310 to 230 lbs in 3 months. A combination of stress and divorce quickened the loss along with the diet. Took me 2 yrs of being back on the idot American diet to bring it back putting me at 300 as of January 1 2022. That day I decided to start back on keto with a purpose. By day to I was in low level ketosis. Blood sugar all over and well felt like garbage. Started that Monday off with a 24 hr fast that boosted ketone levels and reduced by blood sugar. Then follow the Friday with another 24 hr fast. Sunday I decided to do a longer fast that ended up at a 54 hr fast. During that time my blood sugars dropped as low as 57 and ketones climbed to 6 that brought my GKI to .5. So I can say I'm will into the keto diet again and have lost 15 lbs already. My issue is that's finding information on how low blood sugars go and if it's safe while on the keto diet. I never developed any issues because of the low sugar felt fine and kept very good track of both with a meter. Does anyone know about good blood sugar levels?