The others have given great advice. A few things I will comment on as well....

Feed in his tank. It will be better for him and you.

Give him a full week or 10 days without handling, and after he has eaten for you before you try to handle him. When you do, just take him out for 5 minutes or so each day for the first week, then maybe a little longer each week after that. I've had my BP for about three months now, and even with handling almost every day, after about 20 minutes, she'd ready to go back to her house.

Get some tongs or hemostats to hold the prey when you feed him. This will keep the prey away from your fingers and your BP won't get confused what it's striking at.

Get some hand sanitizer and keep it by his cage. Anytime you open that cage, except for feeding day, use that on your hands. This is a good habit for two reasons. 1) it kills any germs on your hands so you don't pass them on to the snake. 2) this provides a consistent scent for your BP to associate with you, and not it's prey.

As others have said, if you can post a photo of your enclosure/tank, and let the group know what your temperatures are, humidity, etc... and what you're using to maintain those, folks here can offer helpful advice.