With due respect, I want to let you know that I am Your Name studying in class ... in your school. I was absent for two days. The reason behind that is I was suffering from high fever. I was not enough good for a present in the class.
It is requested to please consider my attendance during that day. I shall be thankful to you for your kindness.
I would go with the last one, the way its described seems scary and uninviting. and for instance maybe if you were somewhere that you enjoyed or wanted to be the bug would bother you, but in this case they don't seem like an main concern.