I can only tell you if this was me, I would have a serious conversation with the radiology oncologist about this. If you are already fatigued, the standard radiation might be better or more of a challenge, this is a question to ask. Also I agree with @jlgc about the PT, I would definitely ask about that, sometimes the best way to combat the pains that come with movement is to move more in better ways. I would also talk to my doctor about the excessive sleeping, as this can be a lot of different things, from habit to something really serious and a million things in between.
I understand there are long term side effects of the high dose chemotherapies that many of us took 20 years ago. I have a few, I make sure that I discuss these before any new treatment. I am grateful that I didn’t die from BC in my 30s, but I definitely have some constant reminders that even my PCP doesn’t always get the connection, and he is pretty darn good.
I would write down my questions so that I wouldn’t forget, let them tell you about the plan, then any questions that didn’t get answered, ask them. I find most doctors welcome any relevant questions.
Did you have radiation the first time around? Is this a relapse or a new cancer?