Drink lot during day,mainly diet soda. minimum 12-14 cans a day! (bad i know) but dont pee much,always tired!! on meds 4 myasthenia. labs ok! ideas?

Too bad 4 ur bones: Kindly refrain from from drinking that much soda, forget about that 'diet' thing, your bones would suffer badly and you would easily develop osteoporosis, (bone fragility), being tired can be a sign,although the first sign can be a fracture, don't mean to scare you, rather a warning. See your doctor and ask for bone densitometry and renal function tests. Replace the soda with plain water,goodluck