When the Bills scored with ~9 minutes left in the 4th, I was feeling the same way as you. I said I don't even care if we lose at this point, it is so much fun watching Josh play QB and it's amazing he's even gotten us into this position.
My mood took a 180 when the coach made indefensible (in my opinion) end-of-game decisions. In the grand scheme of things, the loss isn't that important. But man, it's hard when an all-time performance by the QB isn't maximized by coaching.