Im turning nocturnal?!HELP PLEASE!?

Help me please! when there was school I would fall asleep at like 10:30 p.m. but as soon as summer started, i would stay up until like 4 a.m and I would wake up at like 12 or 1 p.m.!! i just dont seem tired anymore and i don't know why! How do i get back my body back to when I was still having school because when school starts again, I'm going to have to wake up at 6:30. I'm really worried :\