STOP handling him until he eats; ZERO CONTACT. you should not handle a snake that is not eating as you will further stress them out and cause them to go off feed, and this snake is far too skinny to keep missing meals. he has 20 years to get used to you, he'll be fine.
"running around" is not something you want to be seeing with a baby beep; that is a sign of stress. aside from over handling, baby beeps will not eat unless their husbandry is properly met to a TEE. could you show us pictures of the enclosure? you mention bulbs and a UTH, but how are you regulating those heat sources? ALL sources of heat MUST be regulated by a THERMOSTAT! or a rheostat, but thermostats are preferred.
read through this post and retain ALL the information: https://ball-pythons.net/forums/show...-hatchling-101
mites take a huge toll on beeps; they need time to get their health and strength back, and it wouldn't surprise me if they don't eat right away once the mites are gone.