My snake was fine going over a month with no food, he wasn't weak at all. When I had to handle him after a meal because his jaws went down his throat he was extremely weak afterwards just from the stress of it all.
The OP'ssnake also wasn't weak just the day before, so thats why I was thinking stress.
We also don't really know how the OP went about trying to assist feed.
Yeah a lot of breeders start their new hatchlings off on small adult mice and skip right over hoppers.