What Causes Headaches & Dizziness?

Hello Doctors, please i need advice. i woke up this morning and after i turned my head to the other side, it felt like the room was spinning around, dizziness. And since morning I've been getting dizzy spells when i move my head backwards or sideways, when i bend as well. But i don't have nausea, vomiting or a headache, just dizzy spells since morning. What could be the problem? I'm so worried...