Hi and welcome to the site,
I had rads following chemo, 7 years ago. At the time I was in a trial to have rads twice a day, rather than the normal once a day. It was not a good trial, and I understand they do not do it any longer.
Your concern about being tired during rads - I was. I would have a treatment in the am, go back to my room (I was 125 miles from home so stayed in a motel) and sleep till time for my afternoon treatment. Then force myself to go to the mall, or someplace for a while. I was usually in bed by 730pm though. My husband was staying with me and I finally told him he should go home cause all I was going to do was sleep. LOL
I also had a bad reaction to radiation in that I burned. I have very light skin and I got 3rd degree burns on my collar bone and under my arm, it also burned my esophagus. I am told that I was an extreme case, which is consoling. LOL
Good luck, I know they have come a long way in 7 years and I am sure you will do fine.
God Bless.
Kitty