Eh, you shouldn't feel bad about this. It was an accident, and you're taking all the steps to make it right. What more could we ask for lol. What would make you a horribly terrible person is if you told us you did this, and decided to sell the snake or put it on craigslist or something...
Temp and humidity problems are frustrating! I recommend spraying often when the snake is going into shed, and when the tail is healed, find a substrate that holds humidity better, like cypress mulch. I've had to do this during the drier seasons, and I have to do this again this month. I prefer using sani-chips because they clump poop and urine, and it's easier to clean, but they don't seem to hold humidity very well, even after daily sprays.
What else could you tell us about your setup that could help us help you?