I had my Tx in the reverse order, rad then surgery 4mos later, but like your husband I have that noose around the neck feeling on a pretty regular basis.The PT tells me it is fibrosis of the muscle tissue after rads. The surgical side is much more tight than the side that just took the rads. Physio definitely helps, I am having it now, but it has been 2 months and I'm not out of the woods yet. That choking feeling can be both frightening and painful. It also sounds like he may need some stronger meds. Now is not the time to hold back on pain medication. There is enough built-in discomfort through the treatment process that we should never feel it necessary to "tough it out" with pain of any kind.
Bother the docs as much as you need to, working with cancer patients is their chosen field...they need to hear how he is doing.
All the best to you and your husband.
Fran