It turned out I was correct this entire time. My only problem was the fact that I had been referencing the camera's position relative to the gui, which I didn't realize wouldn't move. I decided that I'd, in the mean time, start working on the movement of the player. When I put the sprite down, it was moving opposite the direction it was supposed to. No matter how I changed it, it wouldn't go the correct direction, and that's when I realized the character wasn't moving--the camera was!
Problem solved in the most hilariously frustrating way!