I didn't have quite the same result as you but I too had a C-section and experienced a scary situation. After my doctor had closed the incision, they were trying to move me from the operating table to my bed. The anesthesiologist told me to cross my arms across my chest as if I were to hug myself. I could lift my left arm but not my right-in fact, the entire right side of my body (down to my waist) was numb. He had no clue as to why that happened. I was probably numb for a good 8 hrs and I was FREAKING out. By the night, feeling was gradually coming back. The next day, everything was fine, back to normal. The only conclusion was that the anesthesia somehow made its way
Your situation is the first I've heard of, being that it's been 3 weeks and like you wrote, you've lost quite a bit of fluid already. I do hope you come through with no problems, that too lasting! I would get after the doctor and/or anesthesiologist!