So many things to say, I just hope I remember them all. I too started getting migraines at 15 (now 4

but after trying many meds found that what worked best for me was mersyndols (pharmacists can dispense them here) & I still take them, all the others just didn't help.
But mine were never as bad as yours - have you been tested (really thoroughly) for allergies???? My daughter (15) started geting migraines at 12 when we bought her a solid pine bedroom suite - it was 6 months before she could go back into her room!! Turns out she's highly allergic to anything even remotely petroleum based (pine is treated with something which has a touch of the stuff!!). She often bangs her head against a wall or the car if she comes into contact (or breathes in) with it & it's in perfumes, deodorants, cleansers & so so much.
The other thing with her is she is immune to pain killers. She may as well have water as codeine forte, or anything else. We discovered this when she had 3 wisdom teeth removed & nothing worked on the pain. She might as well be taking water.
So first if the pain killers do not help, get rid of them.
Second get tested for allergies.
Third, try & think whether anything happened, new furniture, periods starting, new washing powder or new tress/shrubs etc anything about the time that the migraines started that may give you a starting point for maybe fixing things.
Fourth, try alternative medicines, accupuncture, naturopathy, homeopathy, vitamin & mineral supplements (talk to a good health food store about what might help ease migraines.
Fifth, i'd see another dr, couldn't hurt & might help.