Fear of Not Knowing

So I just got diagnosed (finally) with ADHD and I’ve had a hunch I’ve had it for a very long time and im relieved to finally know. I’m grateful as well to have that weight lifted off. However, I didn’t realize how hard I was working on scheduling and doing basic functions until they pointed it out to me. My doctor and I decided to start me on Adoral and I take it for the first time tomorrow. I’ve heard so many stories of people becoming zombies and losing who they are that I’m absolutely terrified of what comes tomorrow. What if that happens to me?! What if I lose my ‘happy Hannah’ as we call it? Am I the only to feel this? How does anyone cope?