Hi Shelby! Your case sounds very similar to mine... I was diagnosed young, stage 3, non-HPV, oral tongue, tx radiation and chemo. I didn't get on a feeding tube, my doctor thought that given my age and relative health I could get by without it, and avoid some of the complications feeding tubes can cause later on. It was difficult, especially the first couple weeks after treatment, but I got through it and had no problem eating solid food again once the mouth sores went down.
In my opinion, I think having the cancer on your oral tongue as opposed to BOT may be a little easier to stay off the tube, since the radiation is really targeted more in your mouth (opposed to your throat), and therefore it is a little easier to numb your mouth before eating than it would be your throat. My throat didn't get really sore until the end. If you stay off the tube, though, you will have to get used to drinking Ensure/Boost, as that will be pretty much the only thing you will be able to eat for a while. I HATED them, which was my biggest problem with weight loss