1. Is it possible for you to access the images of your laryngoscopy?
2. Vocal cord swelling (Reinke's Edema) will not last a year. You now may have developed vocal nodules (Singer's Nodules), vocal cord thickening, polyps or scarring which is preventing your voice from returning to normal.
3. Get a follow-up laryngoscopy done and compare the images, if possible.
4. Reduce voice abuse and exposure to tobacco smoke, if any; take measures to reduce acid reflux
and remember to rule out thyroid