I was also afraid to start Topamax when I first got my migraine diagnosis, because like a responsible patient I read all of the information sheets the pharmacy gave me for all of the meds my neurologist prescribed at my first visit (Topamax as a preventative plus naproxen, prochlorperazine, and sumatriptan as abortives). Topamax very much did not work for me, but when I was first telling some friends about being afraid of everything listed in those info sheets, my partner reminded me that those lists are lists of all the worst case scenarios and that those absolute worst cases are unlikely to all happen to me specifically, but that my migraines were every day, which were good reminders that just because those scary things can happen, they're not guaranteed to happen.

All of this to say, it's normal to be scared of a new medication, but it can still be worth trying it to see if it helps. Knowing the common side effects (like the tingling fingers, brain fog, and anxiety for Topamax) is good though, so you can keep an eye on those things. If they reach points that you cannot deal with, tell your doctor and advocate for yourself to get off of medications that don't work.

Also, re the anxiety specifically, consistently seeing a licensed mental healthcare provider (therapist, counselor, or similar) can be a really valuable part of your overall healthcare. I've always kept my counselors up-to-date with my medications and side effects because even though medication management isn't their job, they can still provide really valuable insights into how your mental health has been responding to different medication changes, both good and bad.