Middle december lost my voice after xmas party then came back another party gone again and now back but right side hurts bit? What could it be?

Vocal strain. Likely just chronic laryngitis/vocal abuse. The pain is a little concerning, but may be evidence of some underlying acid reflux disease with a reflux granuloma. I would definitely see your local ENT for a full exam and endoscopy of your voice box. In the interim try some over the counter Prilosec and/or zantac (ranitidine).
Laryngitis. You could probably be suffering from laryngitis which is a condition due to inflammation/irritation of your voice box. I assume that you are talking loudly and shouting during the party. Those activities put a lot of stress on the voice box causing swelling and loss of your voice.