Nasopharyngeal tumour radiotherapy effects

I have just joined CSN, my first post, I had NPC diagnosis recently, and have started radiotherapy for nasopharynx recently, here in London.    this is Not the first time, because  I had tonsil cancer SCC 7 years ago and went through the chemoradiation followed by neck dissection.     This time no obvious symptoms but for last year had bad shoulder pain on LHS, felt tired and weight loss.  my GPs didnt listen and messed around instead of getting scans done straight away,  seems a tumour has been growing in the parapharyngeal space (left side of nose quite far back into head and up to skull base) and this grew and invaded the space, with suspected mucosal spread behind my nose.   the tumour is tested positive for HPV virus, and my tonsil cancer was also an HPV carcinoma.     I have begun radiotherapy, but regret it now as the effects are far worse as some areas - one side of my mouth especially have already received radiation from the past treatments in 2010, and are reacting much sooner than my experience with severe ulceration on my tongue edge and back of soft palate with bleeding at only 2nd week of RT - have 4 more to go to complete the 6 weeeks of rads.  I fear that such effects of tissues that have already been radiated the first time around, will prevent the completion of the RT program.   I wish I had looked into Proton beam therapy which is not avaialble in the UK, but I could have gone elsewhere in Europe for it.  now other centres will not be able to accept me for PBT as I have already started radiotherapy here (day 12 of 30 rads today), and so it would mean interupting the RT and doctors dont like you to do that, as it give the tumour a chance to come back very quickly.   when i was treated in 2010 for tonsil cancer the main effects were oral mucositis and saliva problems.  this time I will also have to deal with the mucus problems in the my nose, and I am asking for your suggestions and advice with what works and helps, so I can get started straight away.   can you tell me if nasal sprays, nasal rinsing,  (like neti pot) or steam inhalations work best  ?  how about dealing with the dreadful ulcers and bleeding in the mouth. ?  any products that help etc.  I am exhausted and late here but will post again .  thank you.  I am being treated in the UK.