So I'm a high school student and for my biology class I f'd up bad on my last test. So I wanted at least an 85 in the course and I was at 83 or 84 grade before this test. 

It was the last test before our final tasks (culmative tasks worth 30% of our grade) but I think I did poorly because I slept like 4 hours and was unsure for half of the test. I think I got around 65-67% (in Canada this is like a C below 50% is a fail.)

I usually score B+ or A's and I have a feeling my grade will drop because of this last test. Any advice? I feel more afraid now to study for the final tasks because I messed up this unit. 

This is giving me so much anxiety and I end up hating myself because of my procrastination habit. This could've been easier but my dumbass didn't study on the weekend. I'm not in deep deep shit but I defiently need help.