It's possible the original regurge was because of the cedar, I know he kept the second one down and then you changed out the bedding (good!) but it may have caused that first one. Usual other causes of regurg would be temps too low or high, stress or disease.
The hatchling care sheet Deb posted is a really good one. I hope he starts feeding for you again.
I was actually mistaken about the original mulch we used--it was Aspen. I think his temp was too low. Agreed, excellent care sheet from Deb, wish my search results had brought it to my attention a month ago! Thank you for your well wishes!