hello R N Pandey ji
vocal cord polyp develop because of improper use of voice ie either shouting or not speaking in correct way.
surgery is last resort that is true and the surgery is not that problematic so you can go ahead with it as you said that medical management have been tried already.
But still if you do not want it then---
meet a speech therapist and they will tell you the way to make your speech less stressful like taking deep breaths and then speak,they will tell you about relaxation exercises so that the tension of neck muscles can be relaxed ..it helps a lot
Secondly try to live a stress free life
thirdly take medicines to decrease the gatsroesophageal reflux like----
Tab. Mucinac 600 once daily
Tab. Sompraz D (Omeprazole
+Domperidom ) two times a day half an hour before meals
gel) 2 tsf two times a day half an hour before meals
) twice daily
Keep head end of bed elevated.
Avoid alcohol, Smoking
Do brisk walking daily
Go for walk after dinner
Avoid spicy food
Avoid late night coffee
follow up after 7 days.