how far out from surgery are you? were you on high dose steroids prior to your operation? after my first op I had an adrenal crisis from long term steroid use about a week or two after surgery I could hardly get out of bed, hurt all over, short of breath, etc. may not be that at all especially if havent been on steroids lately however stress of operations and illnesses can cause it as well. idk, just a thought. i did a long taper of steroids over 2-3 weeks and after the first dose it was like a night and day difference. again this is just one of those "IF your surgery was very recent and the steroid usage." may not be that at all