My diagnosis was T3 - N0 - M0 one dr believed I was more a T4 he found some damage from the cancer dripping to my spine but we all stuck with T3. Mine also squamous cell Laryngeal Cancer inoperable. I had 35 Radiation treatments targeting my tumor and took out 2 lymph nodes, also 3 treatments of Cisplatin all in 7 weeks.
I think I had to wait 6 or 9 weeks for the PET scan to look for the cancer and I am in remission no cancer end of Feb will be 2 years. I also had to have a feeding tube before my Dr would start radiation.

About 4 months ago I was diagnosed with lymphoma and now I use a lymph pump and it’s great not painful and helps - this can happen after treatment if your lymph nodes are messed with in any little way from radiation along with the thyroid problems.

I wish you the best - you are going to be ok, I would suggest always to get a second opinion especially with radiation because it will cause long term side effects- ask lots of questions about the radiation and choices. I was in a different place than you are so my choices where not so much…. But see what is affective and least damaging.