I am 15 years old and I suffer from frequent (usually daily) headaches, this has been going on for about the past 8-ish months, I visited the doctor back last July and he sent me for an MRI scan, so it has been determined that this is just a thing that will go away and that I shouldn't worry.

I usually take Paracetamol once and thats the headache gone, but recently Paracetamol has not been working as well, dimming down the pain but definetely not getting rid of it. Ibuprofen is not an alternative because it has never worked for my headaches.

Is there anything I can do to get paracetamol working again? Is it possible that I have built up a resistance to it or something?