Heat pads (human type) or UTH (those made for reptile keeping) all NEED to be regulated with a thermostat, not just read by a thermometer. Otherwise they can easily overheat & kill your snake, or start a fire. (heat can build up, wires can short, etc) Safety is important, as is installing them properly (with a little air space for safety- recommended by the manufacturers, btw).
What's REALLY important is to take a temperature reading ON the glass INSIDE the tank where the snake might actually touch it if (WHEN!) they push the substrate back (which they will, sooner or later). You don't want that inside reading to exceed 89-90* max, okay? Snakes like BPs don't always know when they're too hot- maybe because they're heavy bodied & it takes a while to warm up their whole body? Anyway, "burns" are the result, they're painful for the snake, not fun to treat, can be costly (vet care!), can be serious (lead to infection & death) & are best prevented.
Unless your room is totally in the dark, I'd leave the light OFF. BPs are nocturnal, & like most snakes, prefer dim lighting. Just the ambient room lighting should be fine & less stressful. This could be part of the problem. If you still think it's too dark, only use a dim bulb & not near the tank.
Humidity is usually an issue in a glass tank with a screen top- there's too much air-flow. Most using similar set-ups find they need to cover most of the screen with something that doesn't allow air-flow, some use tin foil, others use a piece of plexi, etc. If you look closely at the professionally made plastic enclosures that many use, you'll see how little ventilation there is- you need some, for sure, but that's an easy fix. Knowing that heat rises, it helps to have 2 "vents", one over the warm end will allow warm air to rise up & out, & one vent on the cool end, which will draw in fresh air to circulate thru.
The frequent spraying may also be startling to your snake- the breeder probably didn't do that.

Better to humidify the substrate somewhat, or offer a humid hide, & not spray. If most of the top (screen) is covered to block air-flow, that will likely fix the problem- humidity will stay in where it's needed.
You mentioned the towel that helps weigh down the top, that's why I wanted to make sure you know that snakes can & will push up on tops- they must be very secure. A towel is no match for a determined

lol. You might never see your snake doing this, it's more likely to happen when you're asleep & the room is dark. Anyway, the towel itself is a good idea for adding privacy.
Posting pics:
https://ball-pythons.net/forums/show...-Post-Pictures
Thawing prey: FYI-there are many variations on this- you'll find many of us don't agree on exactly the best way.
I thaw in cool/cold tap water until rodent is soft thru-out (yes, I feel with my fingers to make sure nothing is still frozen inside).
Some keep the rodent in a plastic baggie, so the water doesn't wash off the scent- that's okay too, it will take a little longer to that that way, that's all. My snakes don't care, they're not fussy.
Some thaw in warm water- that actually can cause some spoilage on the outer parts of the rodent, while the inner part is still frozen. Snakes don't eat cooked prey, & many will reject spoiled food.
The time it takes to thaw mice depends on the size- the bigger they are, the longer it takes. (Large rats take the longest, due to size but also the thickness of their fur- it acts as insulation, even in water!) Changing the water when it gets really cold will help speed up the process.
Please don't thaw rodents by "setting them out on the countertop for a few hours" as some may advise- it promotes spoilage because it's the slowest way to thaw. Even if you thaw your own meat this way, remember that you're not eating it raw- cooking kills bacteria- & you're not eating the whole animal the way a snake is. (The gastrointestinal tract of rodents is loaded with bacteria that can hardly wait to be at room temperature to proliferate- don't make them happy. Snakes have a good sense of smell, & know when rodents are spoiled.)
Remember that temperatures change the most rapidly thru water- not thru air. (That's why thawing in water but with the rodent in a zip-lock baggy will take longer, because there's air inside too.) Speed is the best reason to thaw in water. Thawing in the fridge is safe, but very slow at 40*.
ONCE the prey is thawed, you can briefly immerse in warm water (a few minutes) and/or use a blow-dryer to warm it up so it seems alive (mostly the head, where the snake will target). Rodents have a high rate of metabolism- they have warm bodies which is what a snake with heat-sensing pits is searching for. They cool off quickly though, you need to offer quickly once it's warmed up.