@Hopeful310, just do it. I had to reschedule my test, and when I did, I booked it sort of far out. It just felt like it was hanging over my head. Then I impulsively rescheduled last week, when I saw a good time slot I liked come open. I didn't even think, that I would not have any more time to study and I was getting too close to change it. The day before I got cold feet, but it was too late. I got that same red notice telling me no, I could not rescheule. I felt a moment of panic, but then relaxed because it meant I really didn't have any more choice in the matter. It forced me to do it. I needed that.
I still don't have my results, but it feels so good to have that test out of the way. Even if I have to do it again, I at least have that first one out of the way, right? I never have to do that one again! And honestly, while I was taking the test I was thinking that no further amount of study would have helped me at that point. Another week or two weeks would not have made the difference.
Another thing my friend told me - you don't have to do perfectly, you just have to pass. You don't have to get an A, or a perfect score, you just have to pass by one question. So whether you score 100%, or barely pass, it doesn't matter. You probably already have what you need to pass, since you got through school and most peope pass. Trust yourself! Go for it. Try to let yourself be EXCITED rather than petrified! You can do it!