Wow. Are you for real.? Healthy diet and "strengthening the immune system" will NOT deal with a cancer.
Have you listened too and actually read all the advice given to you on this site?
Man, either you get yourself to a Head and Neck specialist right now or it will be too late. And you WILL DIE of this thing.

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!