Wilma,
yes! The PEG tube does not prevent you from eating and drinking normally. Those who have it use it only when they have to. Also most continue to at least drink some liquids normally.
If it becomes to uncomfortable to eat drink normally you switch to the PEG and as soon as you can eat and drink normally you switch back. For most this is also gradual. It is also great to ensure that you get the hydration you need. The feeding tube comes out once it is clear that you get enough calories the regular way, so that time varies. Taking it out is a snap! (literally).
The timeframe you list is extremely optimistic, I am not trying to freak you out, but you are not just treating a cold here. You may be up and perhaps working 2 weeks after the radiation ends. If you are very lucky and even then you are most likely as weak as a dog and are nowhere near where you were before the ordeal.

Best

M