HBOT Questions - did we make the right decision?

Background
My husband (age 61) was diagnosed with Stage 3 tonsil cancer (HPV+) in October of 2011. He had a tonsillecomy followed by 7 weeks of radiation and 2 treatments of chemo. He went through treament well and we thought he was getting better. Then in May he had trouble talking and had pain in his throat. ENT did a scope and said there was a small bone stuck - probably came loose from the very agressive radiation treatment. He had surgery to remove and was getting better again until 3 weeks ago. He felt like he had to cough and blood came pouring out of his mouth and nose. We rushed him to the ENT. Emergency surgery showed some small blood vessels had ruptured. They did an angiogram to make sure the main arteries were ok. They were. Diagnosis was necrosis - tissue/blood vessel damage. Blood was also not getting to his bones. We talked to several doctors - including teaching hospitals and they recommended HBOT therapy. 30 90 minutes treatments daily. He has just finished his 14th treatment. Has anyone had this or heard of it? It's not painful but he seems to be very tired. Doctors all say this is normal but nothing that has happened to him has seemed normal. The more research I've done the more conflicted I am. Some say it is excellent for curing and healing dead or dying tissue. Some other blogs say it is a last resort and surgery should be done first. I thought we had done our homework and made the right decision. Now I am not so sure. Does anyone at all have any experience/knowledge? Please help!

P.S. he has had 1 clean PET and CT but they want to wait on the other PET until after his HBOT treament.