Scary sensation regarding sleeping while ill

This other day I had caught the flu, so I stayed home from school and slept through most of the day... I woke up at 12:40 am, with the weirdest feeling, that it would be impossible for me to go to sleep again for a long time, even though I was quite tired. I found that watching TV made me feel a little anxious, so I got up and went to the bathroom, at which time I for unexplainable reasons started to feel a sensation of panic. I went in the living room to have a smoke, felt fine as long as I didn't think about sleeping.
To attempt to explain the feeling when panicking: it constantly feels like I have a space to fill out, and if I don't I can't sleep. When lying in bed closing my eyes, I feel distant in my own thoughts.

I have experienced this a few times, though not nearly as bad.
I have no health problems in general.