Shingles and Post-Herpetic Neuralgia

I am a 64-year-old female with shingles. I have severe pain in the breastbone and back and a small rash under my breast. I cannot tolerate Valtrex, which fights the varicella-zoster virus that causes shingles. Will I definitely get post-herpetic neuralgia if I don’t take this medication? Will Tylenol help prevent complications? Can I heal without taking these drugs?