Thanks for using Healthcaremagic,
You have suffered swine flu
recently and treatment was specific for swine flu and may be due to secondary infection was given antibiotic.
This is viral infection which can cause inflammation in respiratory tree including larynx
I hope as you have recovered this will also improve with time take voice rest, warm saline gargles and good balanced diet with any vitamin supplements if given by your doctor.
In future take vaccine
Wish you speedy recovery.
Dr. Akhilesh Dubey M.D.