Hey, Phil! Great to hear from you--and we're very glad your BP is eating--at least I'm assuming you're referring to your BP? Please correct me if not.
Hopper mice are not big enough for a BP. Can you weigh it? According to Mykee, a good guideline is to feed a prey item that is about 10% of the snake's weight. Another rule of thumb is prey that is at least the same diameter as the snake's widest girth (diameter) and up to 1.5 times that girth.
If you can get rats, most people think rats are better feeder items for BPs, as their snakes grow better on them. So move at least to a size of rat larger than your hopper mice. Thaw a mouse with a rat to scent the rat. Try feeding the rat first with a well-heated head for a good heat signature.
As for the corn, similar rules apply. Move on up.
I'm sure someone else will jump in here with more info!