Please help! Baby snake regurgitated!

[donutsdad]

I have ordered a thermostat and it's on the way. I didn't realize that my temps were so extreme.
I have also ordered nutribac so that when I feed Donut 2 weeks from now, she can have some probiotics to refill her gut.

I have reduced the amount of aspen I had piled on before. Now it's about just over an inch from the bottom of the container.
My plan is to keep Donut in this smaller enclosure for the next few months until she gets bigger/healthier enough for the 20-gal terrarium I have.

The current ambient temperature is 77.9F and the humidity level is 81%.
I have a UTH that is attached to one side of the container, covering about 50% of the bottom.
I also have a small water bowl inside.

I'm not sure what to do about the high humidity level.

When I open the container, the humidity level drops to 55% and the ambient temperature drops to about 76.1F, but I can't leave Donut unattended for long periods of time with the lid off.
What are some strategies I can use both short-term and long-term to keep a perfect humidity level?

[Bogertophis]

...I'm not sure what to do about the high humidity level.

When I open the container, the humidity level drops to 55% and the ambient temperature drops to about 76.1F, but I can't leave Donut unattended for long periods of time with the lid off.
What are some strategies I can use both short-term and long-term to keep a perfect humidity level?

More ventilation. If this is a "tub" (plastic box type enclosure) just drill or melt a couple small holes for air circulation. You're aiming for 60% humidity, & a little
higher (about 70%) only when shedding. You could try adding one hole at a time, or, if you do a couple at once, you can always cover with tape (on the outside).

Be sure you are measuring temps. accurately & on the surface that the snake can & will touch (ie. under substrate) for temps. -most here use a digital temp. 'gun'.

You are quick to adapt to the changes needed...

[donutsdad]

Thank you so much everyone for your advice. You're all so kind and so so so amazing. It's been super helpful.

I have buried the thermometer into the substrate and drilled a bunch of holes to the top of the plastic container.
While I don't have a thermostat, I have the UTH hooked up to a timer that turns the UTH on/off for 30 minutes at the time.
The temperature within the container is fluctuating between 76F–80F.
I have buried the thermometer in the center of the container a little bit under the surface of the substrate.
I have drilled just about as many holes as I can at the top of the container, but humidity won't go below 64%.

Is this okay? Is there more I should be doing?