Neverending colds and the cost of fatigue

We had a little over a week with no colds or illnesses in the house. I was healthy, the kids were healthy, hubby was healthy. We went on vacation. I needed a few painkillers after two days of walking around, but overall it was great. Now 3 of the kids have a cold again, one came home sick from school, and I have the sniffles. My RA has also been hitting me hard the past few days. My jaw has been particularly awful and today I am exhausted. It's 10 AM and I need a nap. I've read many a comment on how the fatigue is actually the hardest part to deal with. I tend to agree. The pain can be horrible some days, but it can be worked through and to some extent even tuned out because it's always there. When it's bad, I can take painkillers to dull it. I can soak in the tub and read a book or sit under my heating blanket and watch a movie. But when the fatigue is bad like today, it just saps all will to do anything away. It reminds me very much of what it felt like when I had mono in highschool. And there is nothing I can do to make it go away. I just have to rest, nap, and wait for it to pass. And when it finally does, I am bothered by all the things I had wanted to do and didn't get done. 
I am currently reminding myself- it isn't about what I didn't do, it's about what I did do. If all I can do today is feed the kids and watch tv with them, then I can be happy that they are fed and entertained. Now I just need to convince myself once again that it is true.