Confusion.

I want to trust in Him that my exam results will be fine, but I don't want to be over confident and selamba/ don't want to keep my hopes too high up for I'm afraid I will get HUGE smack on my face when I receive my results and realized that I did not get as what I had expected. Is it wrong to feel this way? Does this mean that I'm doubting God? I always gets confused about my feelings like that. Is this what the Devil wants me to feel? There's always a tiny voice inside of me that says,"why? don't you trust me?" and starts telling my bible verses. But then I replied," I DO trust in you but at the same time, I don't want to get a hard slap on my face." So I keep a save distance from trusting God to save myself from regretting not studying hard and stuff. Sigh. Tell me if what I'm doing is right. :/