Sorry to hear about your DW. I've been going down that same road with my mother....it's tough, but with your atitude, you'll make it.
As caregiver to caregiver, I'd like to offer this advice:

Don't hesitate to accept and/or ask for help from family and friends. You can't do it all yourself...if you try, you'll end up hitting the wall and won't be any good to Nicole.

When she's doing the radiation, food might taste nasty or just different to her. This may or may not happen...the closer to the head the radiation is seems like. Don't get your feeling hurt because you cooked and she doesn't like it. Keep strong odors away from her as it might make her sick. Meat cooking seems to smell the worst...oh, and popcorn. Even strong perfume. Hopefully, it won't be too bad if the radiation is away from the head throat area.

If she's going to be in bed a lot, don't hesitate to rent a hospital bed and put in right in the middle of the family room so she can be comfortable, but not hidden off in another room away from the family.
I hope it all goes well for you. You'll be in my prayers. If you need anything or just want to talk to someone you don't know, but knows what you're dealing with, just send me a PM. Hang in there.