Sorry to hear you've felt unwell because of the radiotherapy. I hope that settles very quickly for you as it's just horrible feeling like that. I have read that radiotherapy can cause you to feel nauseated, though.
I'm due for Planning on Tuesday, 20 April but I've had radiotherapy before, 9 yrs ago, for breast cancer (other side) and was fortunate enough not to have much in the way of side effects. I did get a bit underneath my boob, though, but no burns/broken skin. It settled soon after finishing.
I'm sorry I can't offer much in the way of support re vomiting. Can only hope you're OK vry soon and can carry on with life now 
