I have been surviving CLL since 2015. Fatigue is definitely a constant challenge which is made worse by chemo.
I have found it easiest to manage by literally taking it day by day. Keeping a positive mindset and embracing life for what it is has helped me. Some days I can do more than others. I do try to maintain protein in some form in my diet, even if it is in liquid form. And staying hydrated helps. The biggest tip I give anyone (and still have to tell myself) is to listen to your body! When your body says "Rest"... listen! It knows what it needs. Fatigue is not "Tired or Sleepy." When your body can't do any more for the time being it's okay.
My biggest lifestyle change was asking for help and allowing people to help. I also don't drive right now. But accepting that my loved ones are there when I need them and want to be has been wonderful. It's brought us closer.