Mike,
Welcome. How wonderful that you are able to be treated at such a premier facility like Johns Hopkins. One member at this forum who I believe is out of the country at the moment has alot of experience with Johns Hopkins. I believe her husband is part of a trial there now which involves the HPV vaccine. I would assume since you have been treated at Johns Hopkins that you have heard of the relationship between HPV and oral cancers. You should believe 100% that you will see your little boy grow up, no reason not too. Best advice I can give you is take it one day at a time. I know my father was alot older than you when he was diagnosed but a cancer diagnosis not matter when still hits you like a ton of bricks and scares the sh&% out of you. Time will help with this I promise. Stay strong and keep posting. You will find a wealth of information on this website and from the people in these forums.
Radiation is different for everyone they say so take it as it comes. It is no easy road. Are you taking the Amifostine shots to help try and prevent dry mouth or maybe with Tomotherapy that isn't as much of a problem, I don't know. My father had XRT. He tolerated the Erbitux well but suffered the most common side effect the dreaded acne rash. They can eventually give you something for that. He began his Erbitux one week prior to radiation and it was a double dose.
Again stay strong and God bless
Kim