Bridget,
It can take preventive medications such as Topamax up to three months to work. The dosage you're taking, 50 mg per day, if signigficantly below the top dosage recommended for Migraine. So, your doctor may recommend increasing it at some point. It's worth noting that all of the prescribing information and the recommendaqitons from the clinical trials of Topamax for Migraine prevention instruct that the dosage be broken into two doses once you get to 50 mg per day or more. See Dosage and Tpering Topamax for Migraine Prevention for more information on this.
Although a good precentive regimen can greatly reduce the frequency and severity of Migraine attacks, you will probably still have some Migraines. There is no cure. The best we can do is work with our doctors to find treatment regimens that make the attacks fewer and less severe.
You might well find it helpful to talk with a counsel, psychologist, or psychiatrist about developing better coping skills for living with a chronic disease. This is of great benefit to many Migraineurs.
Good luck,
Teri