Hi, welcome to the forum, migraine can be associated with abnormal odor, if so the triggering factors for your headache like specific food, smell etc has to be ruled out. Sulfur odor can also be associated with rhinosinusitis, head trauma, viral infection, or oral problems.
It frequently disappears with successful treatment of the above mentioned conditions. Another possibility of headache would be cluster headache which is present usually on the single side. Pain can last from a few minutes to a few hours.
Relaxation exercises, listening to music, bathing with warm water, massaging with oil etc will help you. You can check your eyesight. Migraine needs to be managed accordingly. Stay away from triggering factors. Also anti depressants, painkillers may be needed against prescription if you are stressed which may be the reason for cluster headache.
I suggest you to consult neuro physician and undergo proper treatment. Take care and regards.
The comments by bsmsl could apply here, however, phantosmia is more consistent with mini seizures. I would just ask someone close if they sense an offensive odor. Chances are if you don't live alone you already know the answer.
Blessings to all,
Nikodicreta
Many people experience phantom odors (phantosmia) as migraine auras. My guess is that your odor is just an aura. You can research phantosmia for more information if you like.
Take care and I hope that helps.