Welcome and thanks for your question I am Dr. German I would be here to help you and give you assistance until you are satisfied, if the MRI was completely normal ,that basically rules out three things that worry most people : a brain mass , an ischemic event ( in which the brain blood flow decreases suddenly and intensely ) or an aneurysm ( which is an enlarged brain blood vessel that could compress adjacent structures producing headaches). So that is a good thing ,we know you do not have any of these conditions.
At your age , most headaches are caused by : tension or stress ( called tensional headaches in which the scalp and neck muscles suddenly contract ) or migraines ( which are caused by an abnormal brain activity and an irregular brain blood flow ). The advantage with these conditions is that they are manageable and perfectly treatable .
There are other conditions that could produce similar symptoms and should be investigated including : cluster headaches ( produced by the sudden release of serotonin or histamine), high blood pressure or sinusitis ( in these conditions,the air filled cavities that surround the nasal cavity become swollen or inflamed ).
In my opinion , you are probably stressing out and over thinking about something that is not there specially with a normal MRI .
What you could do ,in the meantime ,is taking over the counter pain medication like acetaminophen to alleviate these headaches ,place a cool cloth on the forehead and over your eyes and try to lay down until the pain goes away in a low lit room . There are some natural remedies you could try to alleviate these headaches including an herb called feverfew which you can get over the counter in a natural product store .
If the headaches do not improve or go away , You should consult a Neurologist for a further medical evaluation. But right now , that is not necessary.
If you need any additional information I will be happy to continue further and assist you until you are completely satisfied .
Good luck to you and have a good day ! When we finish our conversation if you like the answer ,please click accept so I can get credit for my work.