I've never heard that statistic! There isn't any worry that you will go into ketosis, it is just how our bodies work, and foul breath is only one symptom. Sometimes I have it sometimes I don't, at least I don't always notice it. It sounds like your body is very busy dropping that weight and doing whatever it's doing to give you aches and keep you nauseas and tired. I'm sure it'll get around to coating your tongue before too long and hopefully that will all you need to worry about for the rest of the fast, leaving all that harder stuff behind! I've had the exhaustion and the nausea, both with vomitting and without it. I wish I could tell you it lasts so long and no longer but it is different for everyone I think. Be sure it is needed though and once it's gone you will be energetic again and will be able to rejoice at the cleansing your body has done.