its interesting that it started directly after the tonsils were removed. the tonsils are part of the lymph system and help to detoxify the the lymph. i wonder if somehow your body started to detox thru your feet after the tonsils were removed??
anyway, have you ever done any detox foot baths? i would highly reccomened givign this a try. its very inexpensive. you can do the full baths and/or the foot baths. in your case you might want to do the foot baths on a regular basis for a while and see if it helps at all.
when you do the bath, you WILL sweat, this is by design. sweating is a great way to rid the body of toxins. sweat and seat and sweat, its good. just be sure to end with lots of cold water. keep using cold water until you stop sweating before you towel off. if you are still sweating while towelling off you will feel kind of crappy.