Hi SweetCaroline-
Thanks so much for your question. You are not alone in navigating sometimes complex and troubling side effects related to Topamax. Nausea, weight loss, brain fog, aphasia (trouble finding words) are all common side effects that our community has mentioned.
While the drug has been FDA approved to prevent migraines, it was initially designed as an anti-seizure drug so it's logical that other side effects arise along with it.
That said, there is some evidence that the side effects that accompany Topamax begin to fade the longer you stay on it. I personally have been taking Topamax as a migraine preventative for years and experienced very troubling side effects for the first three months which faded dramatically after that time. That said, I didn't experience the anxiety, blood pressure rise or increased heart rate you mentioned. That is definitely worth mentioning to your doctor.
As to whether or not it's safe to stop cold turkey, we cannot provide medical advice on this site, however, we do have a general informational page on the drug which says it's not a good idea to stop it suddenly without discussing it with your doctor: https://migraine.com/migraine-treatment/topamax.
In general, we would always encourage you to reach out to your migraine specialist to ask him/her for guidance regarding when/how to stop/start any medication.
Hope this helps and so glad you're a part of our community. Please stay in touch!