White coating on the tongue can be cleaned with a tongue scraper.
DO NOT USE TOOTHPASTE OR ANY OTHER FORM OF TEETH CLENING PRIDUCTS.
Your digestive system will stay active if any thing other than water goes in your mouth. Remember for all herbivores the digestion begins in the mouth with saliva. If you want good healing just drink warm water.
If you don't feel like drinking water that is what your body is telling you. Drink as per thirst. Also do not worry to much about BMI. Just go by how you feel, listen to your body and rest will be fine.
A good job in sticking to your diet. I admire that since I have never eaten meat in my life.