I Am Taking Topamax And I Realize That's The Reason

I am taking Topamax and I realize that's the reason for my extreme hair loss. My Dr. is tapering me off of it. I started to take the supplements Selenium and Biotin reading that that should help plus started using a Castor oil treatment on my hair. How long will it take to grow back? I am so stressed that I actually had my first panic attack yesterday.