You need to remove the bedding, ALL bedding, asap.
Once you have her rinsed and treated she needs to go to a completely clean and sterile as possible enclosure. You don't have to put her into a substrate less critter keeper. Just take the substrate out of her regular enclosure and put paper towels in.
Aspen has a lot of dust and small pieces of wood. All of which will stick to the prolapse. If it retreats even a tiny little bit, it would pull all that dirt in with it.
Spraying the Aspen and putting the humidifier in won't help with that at all. High moisture and heat breeds bacteria. Esp. with substrate in there. Normally not a big deal unless you let it get filthy, but right now things aren't normal. Part of her intestine are on the outside of her body.
You can lightly spray the paper towel for keeping things moist. Clean is critically important right now.
Clean the prolapse carefully , apply the sugar paste, and put her up in her enclosure on paper towels. Then try to get the next available Vet appointment.
Good luck with your baby..
ps. you are not a failure. You got help the first time. You are here to get help with the repeat issue. I doubt that wood mite infested substrate caused the prolapse. Just make sure your temps and husbandry are 100% and keep it as sterile for now as you can.