Honestly, it sounds like the snake is defensive striking rather than striking to feed.
And if he's eaten before on his own, he doesn't need to be assist fed. Especially not for missing ONE MEAL. Check your husbandry, give it another week (as in leave him ALONE), change some things up if he refuses again (make the prey warmer, a little bigger (not smaller), try prescenting, clean his enclosure, think about trying live, etc). Monitor his weight and think about stronger measures once he's lost weight. Even then, I'd go 'vet' rather than 'assist', unless you're experienced with assist feeding. Even then, a baby who knows how to eat and is choosing not to, is probably NOT for a reason. Assist feeding is for snakes who don't know HOW to feed.