Lately i have been having to use the bathroom more than normal, lightheaded , tired, brain fog constantly, and had head pain/ pressure what is it?

Dehydration: Most likely dehydration and electrolytes abnormality when your sodium goes down it creates a slight swelling in the brain that will explain the headache and the brain fog that could lead to a state of confusion and end up in coma . Same time when the potassium goes down which fueled the muscle the body will feel weak and tired and fatigue . Drink Gatorade and avoid energy drinks and sodas see DOC.