psyched myself out yet again

What a day...actually more like what a week - I had a Calculus test today. I went into the test totally thinking I was going to ace it, but then there were these two questions I got hung up on. One of them I just could not, for the life of me, figure out what I was even trying to solve (it was a word problem) - the question made no sense to me...I'm definitely not very 'spatially-minded' either, so I attempted to draw a diagram of it and had no clue where to go from there - stupid related rates. I definitely could never be an architect or engineer. The other was an extrema problem...now normally these aren't so bad, but b/c the value given wasn't simply a real number, but rather contained pi, I found myself a little intimidated. I had an idea of how to go about doing it, but was not certain it was right...and by the time I decided that it was the only thing that made sense to do, my time had run out, hence my not getting to fully answer the question...upon returning home, I realized I was right about how to answer it after all - why do I get so caught up in second-guessing myself. So needless to say it made for a brutal day and I came home quite the grumpy child, feeling as though I am officially the stupidest kid ever! - Hopefully, the next test goes better as I really cannot afford another bad mark, after this test, to achieve anywhere near what I'm aiming for as a final. Oh the life of a student - just gotta keep on pressing, I suppose...please pray that I would maintain motivation and focus when it comes to studying - this year, I have found myself distracted far too easily.