Morphine is not the answer, and contrary to popular belief, we do not hand it out like like candy on Halloween. OxyContin either, for that matter.
See your family doc. Make sure you truly have migraines and not other mitigating factors ( a common one is low blood glucose, so if you are diabetic check that first). If they are truly migraine and you suspect it is from a past head injury, see a neurologist.
If you do have migraines, Imatrex is a good fix.