Welcome. I lost my voice for a couple of weeks after radiation, but that was all. I suspect you have heard it many times, but it would be in your best interest to stop smoking. I would guess that alone could hinder your ability to regain your voice. I know that is a difficult thing to do, but if not for yourself, then perhaps for those darling grandsons? I hope someone else will have a better answer for you.
Hang in there!