Hi Tom. Congratulations on finishing your treatmrnt. It's still early. Radiation continues to work afterwards, just as long as you had treatments. For radiation treatment, it took me a few months to start eating by mouth, and was relying on the tube. How is your weight, which can be an indication you are getting enough nutrients, hydration. You may want to see a nutrionist at your hospital to help with diet, and easy to eat foods. ChristineB made a post here, if you look down the menu or go to search for "Easy to Eat Foods."
There are OTC vitamins, beverges, and prescription medications that can boost your appetite like Melatonin, Omega 3 fatty acids, amino acids, caffeine, wine, megace, Marinol, decadron, testosterone. Even smelling or the thought of food can increase your appetite. I think watching the food channel increased mine. Carbs fill you up sooner than fats will, so maybe increase that and or even spray your food with oil. I have a "Misto" which I put olive oil in it, and spay on some foods. this not only increases taste, appetite, but helps with swallowing.
You may have food aversions associated with your treatment, which makes you not like the thought of food, caused by associating the nausea and vomiting with treatment, to the food you ate, smelled that day, so the thought of food may not be pleasant. The same aversion can be with taste.
At one point I was 130lbs, having gone down from 245 in a month, and now weigh about 180. I can cook, eat, so that helps, and used many of the above, but it took a few years. As I like to say, eating is just more than taste, and taste is more than just eating.
Taste is more than eating, and involves many aspects, and should use all to get the most of eating like using your memory, smell, hearing, texture, and the 5 taste buds, actually 6 I believe, salt, sweet, bitter, sour, umami, and fat.
Good luck with everything.