Pretty good. I give it a 4/5 overall

"If only I could live in your dreams and stay in your daydreams too.
If only I could be the reason you smile every morning that you're late to school.
If only I could be the last person in your mind before falling asleep."

Some suggestions I have would be maybe to change those lines around a little.. example:
"If only I could live in your dreams and your daydreams too
If only I could be the reason you smile, the reason that you’re late to school
If only I could be the last person in your mind before you fall asleep."

Saiya