I had a complete thyroidectomy back in 1982. The surgery went fine with no complications. I woke up to find that I had 2 drainage tubes coming from my neck and I had to sleep in an upright position. I was not in any pain at all.
I was prescribed LevoThyroxine and it took a while to get the right dosage, but all soon settled and the scar healed beautifully, its very thin and now barely visible. A Mum at my daughters school had the same operation recently and her scar is even smaller despite her having a goitre removed.
Keep tight control of your blood sugar levels as this will help you to heal better. You might want to have liquid meal replacement or make up healthy yogurt and berry smoothies and liquidise wholesome soups for a couple of days. Ice cream is good too.
Good luck with it all, thinking of you, please let us know how you get on x x