Any insight on how to deal w/lymphedema, swallowing and mouth ulcers?

Hi all. We are new to the group. First time posting. My husband is 62. He had surgery and 35 radiation treatments for Stage 3 VC cancer. Radiation ended 6 months ago. He has had difficulty with lymphedema and swallowing the entire time. He coughs all the time and has so much mucus. He had a temporary feeding tube for a couple of days but decided to get it out. He has been back and forth between a liquid diet and solids for 6 months. At present he continues to struggle with swallowing and mouth ulcers. Constant coughing, and fatigue. He is/has used magic mouthwash, xylimelts, compression garments, massaging, exercises. He has pain meds of Oxy and Methadone. His pet scan at 4 months showed only inflammation. He has another CT scan next week and follow up with the oncologist. We have been to the ER a few times recently with breathing issues related to the swelling. The oncologist does not provide any guidance as to what can give him some relief or how long this will continue to this degree. We are wondering if anyone else may have similar issues or can offer any advice. Thank you in advance.