First paper of the semester

I am so sad beyond words because I failed to score the easiest paper that took up 20%
They say it's no point brooding over it but I REALLY CANNOT BELIEVE I WAS SO CARELESS!!!!!!!!!!!!!
One example: when (x^2+y^2)^2
Answer is suppose to be (x^4+2x^4y^4+y^2)
SEE THE FACT I COULD STILL TYPE IT ALL OUT YET......... I went to put
X^4+y^4.
Even the most BASIC and simplest rule, I got it all wrong.
Not to mention, that was the first working
so I screwed the whole qns because everything I wrote after that was all wrong.
:'(
I did practice enough, I was all ready..
I did the whole exercise book with more then 50 questions TWICE.
Yet,I failed to do well:(
So disappointed because I really don't want maths to pull down my other subjects which will eventually drag the gpa down.
When gpa decreases, it means that I wasted all my effort in semester 1.
:'(
My heart is sinking:(((((
Nevertheless, I must score A for my last 2 quiz, do all my assignments, participate in class and lastly do well for my mains.
Sigh....
Never been so depressed about my maths.
I KNEW ALL OF THE CONCEPTS IN THE GRIP OF MY HANDS.
But due to my usual careless mistakes, I always don't do well:'(