It is very sad to me to read that someone as educated as yourself (I make that assumption because it sounds like you are in medical school based on this post) would purposely drag yourself to school when you admit that you felt terrible and were a mess. We can't prevent this virus from spreading unless people start taking responsibility and make it a point to stop spreading their germs.
Stay home if you are sick. None of us want your germs.
Believe me, I wanted to stay home. I tried calling the school before I left, but nobody was there at that time. This was a mandatory lab, and missing it would have resulted in automatic failure of the course. When there is such a strict policy, there's nothing you can do, doesn't matter if you're sick. One of my classmates had an appendectomy in the middle of one of our systems, and she missed about a week of classes, including 2 mandatory labs. She was told too bad, she needed to retake the course because she couldn't make up the labs, even though she had surgery! The person running the lab let me sign in and then sent me away, so the school thinks I was there. So it's not like I actually stayed in the lab, I got there early, and wasn't there for very long.
I agree with you it's terrible to go in when you're sick, but with such strict policies, there's really no other option. People come in all the time with all sorts of nasty diseases, just because if you don't, you risk failing.