Today i felt like sensation of fullness/headache and now i'm having this pain on the right side of my head. i'm worried, could it be an aneurysm? help

Rule out rupture: A headache can be a clue to seek medical evaluation for aneurysm rupture. Typically, these are severe, quick onset headaches and are usually paired with mental drowsiness, confusion, nausea, vomiting, and neurological symptoms. A quick trip to the E.R. for a CT scan (of the brain and a CTA of the arteries at the same time) will put you at ease.