Why do I Feel Guilty?

So today is the second day in a row that I have stayed home sick from work. I have a bug that is agravating my asthma, fogging my brain, making me tired, making my body ache, etc. So I am taking a couple of days for me, and to try to feel better. The question is, "why do I feel guilty?"

Why do I feel guilty that...
1. I am not getting anything productive done around the house?
2. other people have to cover tests for me at work, as I have done for them in the past, and will again in the future?
3. that I slept for 14 hours the other night, and after trying to get up and go into work this morning, I went back to bed for 3 more hours?
4. that when I feel even a little bit better I don't think about trying to take care of item 1 or getting to work for item 2?

I will admit that in general I don't take the time I need for me, and to stay healthy, so I think when I do take that time, like now, my guilt button gets pushed.

I'm off to drink more fluids (although I'm not sure what else I would be doing with them) get some rest (there's nothing on tv during the day worth watching) and try to ignore the nagging guilts.