Why am i feeling extremely exhausted, headaches and dizziness all day?

Many things: You could have untreated migraine, get insufficient sleep, poor diet and insufficient fluid. Also depression or mood disorders may contibute. Limit alcohol intake and soda, drink water, eat fruits and vegetables. See a neurologists if you get headaches more than 4-5 x a month and have symptoms like light or sound aversion and dizziness or nausea.