Not sleeping great

So it id currently 5:42 am, i have been awake since 4:20 am. The other day i woke up at around the same time and i cant get back to sleep at all. Im 16 and still in school so i have to get up at 7:00 am to get ready and i go to sleep between 8:30pm and 10:00 pm. I have no idea why i keep walking ip like this and it is really annoying because i have a long day in school ahead of me and i cant concentrate when im tired. When i was sleeping earlier i had a dream about putting myself down amd insulting myself but i dont think that is why i woke up. At the same time could it be the reason? But i didnt have any dreams last time so im confused...i have a headache now and know i have to get up soon but im going to be so moody and emotional all day because im tired!!

Does anyone know why this might be happening, if so please help because i really need to sleep😕

(P.s i apologise if this makes no sense i am tired and camt think straight).