I had 6 weeks of radiotherapy (60 doses/30 each breast), and had this after 6 months of chemo and ongoing Herceptin. I can say I was completely tired and would rest in the afternoon after the morning doses. Like @KarynJ I live on my own also, and coped on my own with all my chores, cooking and shopping. I didn't work throughout treatment either. I agree, do what is best for you, you won't get any medals by working if that is not what is best for your own personal situation.
In hindsight, if I had a job that was conducive to day shifts I may have been able to work and have the radiotherapy in the afternoon, and a nap before dinner, but there would be no way I could have done all that, plus keep up with self care and running my house and cooking for myself. If you live on your own it would be near impossible. Everyone's situation is different.
All the best with what you choose to do, perhaps having a day off on Wednesday, to recuperate could work out well for you.