Hi Rondi (mom of three),
Welcome to HealingWell and the headache forum. Unfortunately I have been in your situation.
I take Topamax without too many side effects, though it isn't very effective either. I made the mistake of increasing my dose too quickly, so if you do decide to take it, increase it slowly or you may go through so crazy side effects. I used to experience forgetting words and events and have decreased my dosage so that doesn't happen anymore. I have lost 40 pounds and it helps balance my mood. I have never heard that it stops your contraception from working. I've been on Depo Provera and it for at least 2 years and not had any unplanned pregnancies.
I take Depo Provera for birth control. It is progesterone instead of estrogen and is given in injection form every three months. I don't cycle like I used to so I don't get menstrual headaches once a month and never get periods. Some people gain weight with Depo Provera, but I haven't experienced this, maybe because of the Topamax.
My neurologist also told me about a study in which patients took Amerge everyday as a preventative. As long as you're not on an antidepressant it can work like a charm. And, as long as you take it everyday you won't get rebound headaches. My neurologist has also told me that of the medications which cause rebound headaches, triptans have the best recovery time. They get out of your system in a few days and the rebound headaches go in a few days, unlike codeine or caffeine which can take weeks.
Sorry for being so long, I hope this helps. Good luck with your search for a solution.