I get severe headaches/migraines, as often as every 2-3 days which are not relieved by nsaids. i also have a mild headache all the time. is it possible that i have a brain tumor?

Seek help now: Anything is possible with these symptoms. Please seek medical help asap. This is nothing to fool around with.

Thankfully not likel: Fortunately having a brain mass is far down on the differential diagnosis. Mass lesions cause additional neurologic symptoms and signs that have a propensity to progress. Other causes of chronic daily headache include transformed migraine, rebound headaches from overutilization of the same headache meds, cervical spine disease, and sleep apnea to name a few. Please meet with your doctor.

Get checked out: A good start at finding potential headache triggers would be to maintain a diary. Every time you have a headache write down what you were doing, the foods you ate that day, alcohol, smoking, caffeine, stress, how much sleep you had the night before, eye strain, etc. Try to find patterns in your headache so that you can learn what things to avoid. Get checked by your doctor.