Why does it hurt so bad?

Why is it that sometimes, when you're doing something good for yourself, it hurts? I'm giving up my achilles heel and I'm having my moments when I forget why. My addiction? Caffeine, most specifically, the nectar of the gods, coffee. Why would I give up such a delicious must have? One word: sleep. I need uninterruppted, non-sleeping pill assisted sleep. Whenever I take a sleep aid, I end up sleeping 10, 11 hours and I feel heavy and drugged for hours after waking. I just want natural sleep and the copious amounts of caffeine I was consuming was not helping me in my aims. Last night I slept like a baby, why? Because Monday morning I got up early and did 45 minutes of cardio. Slept ten hours last night, but instead of feeling like a zombie upon waking, I feel refreshed and ready to go. Tommorrow morning, I'm going to repeat the process so I can get my body exhausted by natural means and get my much needed restful sleep.