Hello Frank - yes you found the absolute best place to be. You also just joined a really big and really supportive family who care about you and helping get you through this upcoming war with the least physical and psychological damage possible.
We've all stood in your shoes, so we know what you're going through now and about to go through later. They have helped me immensely.
When they tell you to eat, eat, eat, listen to them. Once radiation and chemo start the side effects are going to make you lose your taste and your saliva and your throat is going to hurt. All these things together make you have no desire to eat, so you will lose weight. the goal of course is to not lose so much weight that they have to hospitalize you for malnutrition and or dehydration and/or put in a PEG feeding tube. If you can get fattened up right now, you will be a happier camper later. Since my surgery Sep 20th and with 3 weeks of rads I have lost 16 pounds, but I had an oral infection post surgery that brought on my weight loss earlier than planned. My nutritionist fusses at me every week. I am just choking down food every day as I have no desire to eat.
I have a very similar diagnosis as you, tonsil cancer, SCC with
HPV-16, but no lymph node involvement at this point, so I am getting rads only, 70 Gy, just like you. So far the only radiation symptom I have is a sore inside of my left cheek. It feels like it would if you accidentally bit it real hard, an open sore that hurts. I've found that rinsing with salt water baking soda solution helps. I added some oral lidocaine to the mix, that helps numb it before I eat and before going to bed at night. that way I don't have to take the oxy they have prescribed.
Start reading and educating yourself. Get a spiral notebook to write down all the questions you will have from reading, cause you're going to have a lot of them. Take that notebook with you to write down what your doctor and therapist tell you so you can keep it straight.
We will help you along the way.
take care, Tony