sleep aid

i put my head down on my desk in my language and culture class and i really really fell asleep because i woke up at the end of class and i had all these sleep marks on my skin. i hope i wasn't snoring. so then i went to the library and laid down on a sofa and tried to go back to sleep and i totally could not sleep at all! that's so strange. it's like i can't sleep when i should be able to and i can sleep really well when i should not. i need to record my teacher's lectures so they can help me go to sleep at night.