When does it get better?

I've been looking forward to starting my fire academy for months since applying and I knew it was going to be a lot of work. But I am a few weeks in and it's not what I really expected. I find myself pushing myself not so much to learn but to not give the instructors a reason to punish me. I dread going to class because of the fear of them finding the spot on my boots that I couldn't get to shine as well as the rest. I know it is a paramilitary organization but at what point does it become redundant? My first week I was excited everyday before class. Now it has gotten to the point where I see it as a boring chore and not so much a step to further my career. I have never had so much stress and anxiety since starting this academy. Are these signs that the fire service isn't for me? I am scared of diving deeper into this and things getting worse.