Dizziness all day.

I’ve been getting dizzy all day. Only when I lay down though & whenever I turn over. But if I tilt my head a certain way while sitting down, I’ll get dizzy. It started last night when I was sleeping & got dizzy for a couple of seconds. I really don’t know what to do & I want it to go away before Monday because I have school. I’m scared to even lay down because the dizziness is so intense & uncomfortable. Even though it lasts a couple seconds every time. Any ideas on what to do?