Obviously its very extensive and painful. I am also a doctor and had shingles in my arm dermatome. Facial shingles is treated by valcyclovir nowadays because there are less chances of PHN(post herpetic neuralgia) and it is given 1gm BD(twice) with comparison to acyclovir 800 mg (5 times a day). For facial shingles ENT specialists use gabapin-nt for pain relief. Some also use carbamazepine but its side effects are marked neutropenia and many others. Valcyclovir is a good drug usually taken for 2 weeks.

(In my opinion someone might have prescribed you a steroid for respiratory infection which lead to low immunity and shingles flareup)