All stuff that should have been figured out BEFORE bringing an animal home.
PLEASE DO NOT try assist feeding this poor snake again. You are causing WAY more damage than good. Leave the snake COMPLETELY alone for a week and try offering again. If the snake doesn't eat try again in a week. Repeat...
NO HANDLING during this time. Wait til the snake is eating consistently before handling. You'll have this snake 20+ years, plenty of time for handling.
There are 2 major reasons snakes don't eat 1) is husbandry and 2) is stress.
Your husbandry sounds pretty good, but did I read that there is only 1 hide?? You need 2.
So, now the obvious answer is STRESS!!! Leave the snake COMPLETELY alone so he can relax and get comfortable. A scared, stressed snake will NOT eat, and you've got yourself a scared, stressed snake.