"Out of whack" means the same as "out of kilter" i.e. Not functioning as they should. In this context Wenchy means that her insulin levels are not within acceptable parameters.
The body, specifically the Pancreas, produces insulin, insulin uses up surplus blood sugars (ie those blood sugars not consumed in the form of energy which the body then attempts to store as fat).
Produce too much insulin and you will suffer from:
Hyperglycemia ~ typical symptoms would include Polyphagia - frequent hunger, especially pronounced hunger, Polydipsia - frequent thirst, especially excessive thirst, Polyuria - frequent urination, especially excessive urination, Blurred vision, Fatigue, Weight loss, Poor wound healing (cuts, scrapes, etc.), Dry mouth, Dry or itchy skin Impotence (male), Recurrent infections such as vaginal yeast infections, groin rash, or external ear infections (swimmer's ear), Kussmaul hyperventilation: deep, rapid breathing, Cardiac arrhythmia, Stupor, Coma
Produce too little insulin and you will suffer from:
Hypoglycaemia ~ typical symptoms would include: Nervousness, Fainting, Feeling dizzy or confused, Hunger, Confusion and trouble thinking clearly, Headaches and vision changes, Mood changes and Sweating.
Ultimately both conditions, if untreated, can lead to heart damage, gangrene in lower limbs and sudden death.
Sensible self treatment would be to reduce those foods which increase blood sugar levels ~ for example stopping eating chocolate..
Boring and not a rant I know but you did ask.