I have only been taking Topamax for one week, I have horrible mig...

I have only been taking Topamax for one week, I have horrible migraine headaches. I feel very exhausted from taking topamax, and have HORRIBLE HEARTBURN, and I love pepsi, and it doesn't just taste flat, it tastes horrible, like I'm sucking on pennies! I unfortunately think I'm going to have to quit taking topamax, because I just feel so horrible....I can sleep 8-10 hours a night, and then wake up, and feel like I didn't sleep at all! Does anyone else know if these side effects get better as you keep taking the meds? Help!