Hello again!

Thanks to everyone for the quick advice on my last post! I'm going to keep a close eye on Apollo's cut and I'll give an update when I see some progress, possibly after he sheds.

Going through random forum post in my free time, I actually thought of another thing I could use some help with. I'm having a hard time keeping a constant humidity in his habitat. It fluctuates a lot between 40% and 70% and I know 40% is waaayyyy too low, and it is kinda making me nervous because he hasn't shed with me yet but I'm guessing it is going to be soon since he is young. I have him in a 20-gallon long terrarium with a screen lid and cypress as a substrate. I have a water dish in the middle of the setup. I also spray down his cage 2-3 times a day and I keep a humidifier near his cage. It usually hits around 70% if I have the humidifier on full blast for too long but even turning it down the slightest bit causes the humidity to fall too much again.
Any idea on what might help?