Steve,
Your just about at the point where your throat should slowly start feeling better. as mentioned before, we all heal differently and the time frames fall into that also.
We all " Cook " for several weeks after our Radiation Treatments. Some people start to feel a bit better after 3 weeks out, some 5 weeks out. I seem to remember falling in between that at around 4 weeks. You can't see them, but your throat has sores in there as well as your mouth.
When I used the Baking soda and Salt solution, I would rinse/ gargle and then spit. Then I would sip a little more and let it run down my throat, seemed to help me. I also did the same with the Biotene mouthwash.
I hope you start feeling better soon.
My Best to You and Everyone Here