HIDA scan results improve ?

I am a little confused. About three years ago, I had pain/burning (not disabling) in my upper right chest/back along with nausea. Did an ultrasound on the gall bladder - showed "sludge" - and a HIDA scan done - percentage came back at 45%. Was told surgery was not needed. The pain/nausea/bad digestion has come and gone over the last three years, and has recently gotten much worse. My Dr. said it was classic gall bladder symptoms, and had me re-do both tests just so we had current results before we scheduled surgery. Ultrasound on gall bladder showed NOTHING, and the HIDA came back at 77%????? I was just not expecting the percentage to get better - assumed it would just get worse with time. Has anyone experienced this? I do NOT want to have unnecessary surgery. I have been put in Nexium - Dr. thinks I may have an ulcer??? I just feel like I have a piece of hot coal sitting in the upper/right/underneath lung area - mostly all of the time - and nauseous and losing weight.