Having had breast cancer and colon cancer in the space of 18 months, I'm extremely familiar with fatigue 🙄😏. Re exercise, I find swimming very therapeutic, mentally and physically; also a walk, even if it's only 10 minutes away from my home and back again. I've also found that sticking to a routine, going to bed at the same time every night, getting up at the same time every morning, having a nap for the same length of time at the same time every day, eating at the same time every day. When I do a physical activity, e.g. housework, I do it when my energy level is good (for me, it's morning), as I find that my energy level decreases as the day progresses so that I'm whacked by 5 pm ☹️! Hope these suggestions help.