@justwow Hello . First off this a very winnable battle. In particular, if this is HPV +16 as you stated. Google can certainly take you down the rabbit hole with negative outcomes. Your odds are extremely good ! HPV 16 Cancer recurrence is less than 20% in most studies.
If this is any help here is my story which is very close to your current situation....I am 58. I was diagnosed with Stage 4 HPV 16+cancer of Base of tongue and Neck March 2023. I had TORS(robotic) surgery April 2023 to remove base of tongue 3cm tumor ( partial glossectomy )and lymph nodes through right neck dissection. 2 of which had cancer. I opted out of any Chemo treatment. I chose Proton vs Photon Radiation as I feel it is much less damaging . In my opinion Proton is more targeted with less side effects. However, It is a battle as insurance companies do not want to pay for Proton when Photon is 50% less costly or more. Proton is like a pencil beam hitting the target and stopping. Photon is more like a flashlight beam which travels through the target area. I had to drive an hour to Proton treatment. Alot of people drive much further. I had 30 rounds ( ending July 2023) of Proton Radiation to "cleanup" any cancer that may have been left behind from HPV16 base of tongue and Few Lymph nodes . l was very worried about going on a feed tubing , Dysphagia and Not being about to swallow (eat or drink). I started doing mouth, Neck, tongue and swallowing exercises prior to proton Radiation. You may need to seek a Speech therapist as they can help with this. It was a struggle to eat during radiation and I FORCED myself. You will lose appetite and everything will have no taste. Now the good news... As far as today two years out. I can eat and drink about anything I want. My taste buds are about 95% , My throat mucositis has almost gone away, Saliva production 95% and My stamina is back to about 95% . I have no issues with speaking, eating, moving my mouth or raising my arms as you mentioned you were worried about. I will continue to have a throat scope and CT scan every 6 months for two more years or so. So far no evidence of cancer remains. You should also ask about the NavDx Blood test for HPV 16. It will become more important once you have completed your treatment to monitor any HPV 16 cancer activity in your system. My NavDx blood work continues to show no sign of cancer.
Make no mistake this will not be a fun 6 months or so. However, You will make it and things in a year will be looking up. Some things may not taste the same, some slight neck or throat discomfort but you will be alive. There will be a new "normal" but It beats the alternative. Lean on your Faith

@justwow I concur with @jonesja This is winnable. Welcome to the Head and Neck group. You can get a lot of help here from patients who have gone through what you are going through. Myself included.
MD Anderson or Johns Hopkins are both great treatment centers. You are blessed to have these options. Now you have to wrap your head around the fact that your life focus for the next few months is to rid yourself of this cancer.
You can always start your own discussion in this group at anytime you need specific attention / answers. Please don't hesitate to do so. It often leads to more and faster responses than being on another discussion.
In the meantime, as Winston Churchill often said, "Courage." You can do this. You will be stronger for it, I promise.

@justwow Hello, if it will be a help let me pass you my experience; I had radiotherapy all the way and rejected any intervention but as a result after 3 years i have developed Radiation Induced Bracial Plexus in other words I have lost the ability to use my arms.

During and after radiotherapy for some time I couldn't swallow, taste etc. but within the following 6 months I was over 80% recovered from everything until one day(3 years later) I started feeling tingling on my neck and within next 18 months I have lost the ability to use my arms. So there is no guarantee also for Radiotherapy, nevertheless I have been told that a cut can heal but for a burnt nerve there is no coming back; I really want to verify this with the doctor that has given you the heads up on this matter, if you could pass me his/her details I would like to get in touch with him/her because whenever I talk to a doctor about RIBP they seem to be surprised, I have never met a doctor that is aware of this side effect.

In short, if I would go back in time; initially I wouldn't like to go trough this but since it happened I would go for an intervention since the side effects are more or less proceeds the same way.