ya know, it sounds like maybe some specialist consultations might be in order.
endocrinologist....cardiac dr....kidney dr (altho they can tell a lot by just doing a urinalysis).

i would definitely persue and answer. somethings seems out of whack.
i don't understand what a diuretic has to do with sufur antibx?
who wanted you to take the diuretic? did they also tell you should balance the diuretic with potassium?

keep us posted. don't give up.