There are doubts about the idea of trigger foods reating to migraines - some doctors now think the foods are craved before migraine due to hormonal imbalances - much as in pregnancy (the hormonal effects of chocolate are well documented and the it is often quoted as a trigger by many sufferers) So rather than being a cause the cravings are another symptom of the migraine.
My partner suffers migraines - he has one right now as it happens... He is fortunate though in that he has a definate early warning when his left eye goes cmpletely blind and then about half an hour later the sight returns and the headache begins - his normal way of dealing with this is to take very strong painkillers when the sight goes and that minimises the headache when it arrives.
With the nausea often ginger and peppermint teas can help or smelling neat peppermint essential oil
It may well be worth getting hormone levels checked out as these can be the route cause. Homeopathy can also be an excellent solution if you can find a good practitioner.
Good Luck...