This isn’t your first test. Look at your record before you let doubt do the talking.

Doubt speaks with confidence and no evidence. It presents the situation in front of you as unprecedented, which is almost never true, because you have been through versions of this before and got to the other side. Your record exists and it disagrees with the forecast. The problem is that fear does not bother consulting it.

Before the next thing you are dreading, write down three occasions you handled something similar, with dates if you can. Read the list rather than trying to feel better. Facts are harder to argue with than reassurance.