Was Diagnosed With Shingles Today. Prescribed Steroids, Valtrex And Percocet

Was diagnosed with Shingles today. Prescribed steroids, Valtrex and Percocet for pain. I told my doc I get hives and itch from morphine (clearly stated in medical records too). I took half a pill at 6pm - managed my pain for 3 hours: Took 1/2 pill at 9pm. My scalp is itching and behind my ears a bit and my left eye- my pain is coming back and I’m not sure what to do? Can I Take benedryl to relieve the itching? Can I take another 1/2 pill so I can alleviate my pain?