My drop foot hurts. could it be a peroneal nerve injury?

It might: But there can be other reasons for your dropfoot to hurt. There could be increased weakness that can change the interface with your brace and/or shoes, or your gait can change causing parts of your foot to be subjected to more stress. Bring this to your doctor's attention.

Maybe: Peroneal nerve injury can result in a foot drop. If you have a foot drop with pain and no diagnosis, then i would recommend seeing your physician as soon as possible.