Hi Ben,
I just finished up 30x IMRT on Dec 27, following a partial left glossectomy and a neck dissection.  I told the doctors that I wanted to push through this without a PEG and they happily let me.  Some days were tough, but if you remain tough and look at the water and shakes as medicine, you can do it.  I was lucky not to need chemo, which I'm sure made my journey a bit easier.  
I am a month out of treatment, still have a few sores, tongue mobility is poor but steadily improving.  Just yesterday I was thrilled to find enjoy some scrambled eggs and cheese and a strawberry milkshake with taste and all. 
You will muscle through this and be on the other side of treatment before you know it!!
Sally