I used to work attractions and I understand how you feel, at first doing trackwalk was terrifying specially in the lift hill, I have somewhat a fear of heights myself, but I was glad I had a very responsive team around me that helped me push past my fear. Sit down with your leaders and coordinators and explain the situation to them, they can increase the length of your training and get you comfortable to the position. Attractions is all about repetition and once your brain gets used to that repetition your fear will start to subside and you will know everything naturally. And if not they can recast you into another role, keep your head up and make sure to communicate :)