You are an elderly Pre Diabetic, overweight woman.
Past history of Herpes Zoster
Now complaining of pain around the area of chest and upper back.
This may be a referred pain
from Ramsay hunt syndrome
or neurological pain from Herpes infection itself.
Considering your age and Pre Diabetic status you run a risk of cardiac disease.
ECG and ECHO are advised.
Consult a Cardiologist