I know how you're feeling, Mere. I used to be a chocoholic with an insatiable sweet tooth, and just last night sat at the table inches away from a plate of brownies and had absolutely no desire to eat one. That sure was bizarre.
My advice only advice is make sure you eat, even if you don't feel like it. I know a lot of people recommend nutritional shakes like ensure or boost to make sure you're getting enough vitamins and minerals. I can't tolerate most of them, so I have to make an effort to consume small amounts of the foods I can tolerate every 2 hours or so.
If you start feeling worse, or having more symptoms, definitely consult with your doc. No appetite is definitely a red flag, in my book. Hope you get it figured out!