I don't think they're stupid questions because your thinking isn't any different really than the majority of trainees out there. It's really about adopting a different mindset. One that places progress above anything else. The effects of one workout doesn't matter. It's the accumulated progress you make on a whole lot of workouts strung together over time. Once you begin thinking that way, you see that anything that takes away from that progress is bad, whether it's not doing enough or adding things because you feel you should be sore or it should be harder.
But it will get hard, so don't worry
It's too bad that you have a finite time period on it.