Don't feel bad! Last year I got a kidney infection, I ignored it thinking it was a bladder infection and just drank cranberry juice. Well the day my boss had specificly asked me to cover for him so he could go to his daughters graduation came (he had asked me a month in advance) and I was in so much pain I couldn't stand, Patrick took me to the emergency room and it turned out I had to stay in the hospital all day and night for observation, they were afraid I was going to die!! But even through the pain I couldn't help but feel soooo guilty for not being able to go to work.
Whats worse is two months before that I had basicly had a nervous breakdown(my ex had been harrassing me with nonstop calling, my parents were still mad at me for leaving my ex, Patrick hadn't found a job and we had only been together a few months, I was the only one working and I was making a pitiful amount of money, plus I still at that point believed what my ex had always told me about being worthless etc) I was soo sick from it it was extremely hard just to roll over in bed. I stayed in bed sleeping 23 hours a day for two weeks, and could barely eat, Patrick had to help me to the bathroom even! And what made it all worse was feeling like I was just being lazy which made me even more stressed etc. In the end I turned off the phones ringer, and spent two days just doing what I wanted to do (lay there and not worry about anything) and thats what finally got me better.
So don't feel bad! Sometimes your body needs "me" time, even if your brain and heart don't want it, your body (and doctors!) know best!