When something good is about to happen, I'm afraid that something bad might happen which will result in that good event not happening.
What do you call this fear?
>pass exams well
>accepted into X
>afraid that something shitty will happen (I don't even know what) that will result in me not getting into X, even though I know there's no reason for it to happen
>>16858572
Anxiety.
Really what it boils down to is fear of the unknown. Sort of like a fear of the dark.
But rational adults aren't afraid of the dark. Because monsters don't exist.
Likewise, the things you fear don't exist. Never fear the unknown.