Your timeline has me very confused. The way I understood it the snake was fed the day before you picked it up and took it to the vet the day after. Now today it struck at you.

How is it you know when the last feeding was but say the breeder didn't? Usually young snakes are fed every 5 to 7 days.

I highly doubt your ball is striking because its hungry. It is probably out of fear. That will go away as it learns you mean it no harm. Usually a few weeks to a couple months. Another possibility is a up coming shed has it grumpy.

Why go to the vet? Did you see something you thought was wrong?