Last week, I had a severe headache in the night, took a couple of Advil and a hot bath, was able to sleep, but the severe headache remained on waking, so I took Advil throughout the day, and it eventually subsided. Since then, I have been experiencing dizziness when turning over in bed, but at no other time. The feeling is like the tide is rushing out and rushing back, not like falling. This has never occurred before.