Well, we were all Clueless at one time so don't worry about that.
It could have been the temperature if it's cold they don't react much but unless you are freezing I doubt that that's it. Mine outside in the freezing cold are still managing to grab a bite. My guess is that the trigger hairs weren't set off. That is of course just a guess I am by no means an expert. Maybe somebody else might know the answer to that.
When you get exhausted traps leave them they can still benefit the plant by photosyntheses (getting nutrients from light). When they start turning brown or black, clip (don't pinch) just the trap off not the leaf. The leaf will last longer that way and continue to benefit the plant.
Your plant is not dying at least not from hunger or from what you've mentioned. Trust me you'll pretty much be able to tell, they look pretty pathetic when they are getting ready to die.