Fish > Grades

I have a project for class which needed us to take care of an aquatic ecosystem. So basically we were tasked to have one small tank, two fishes, and one aquatic plant. So my parents got me two phantom tetras and one Vallisneria (I reused a tank my uncle used to use). Then I proceeded to tale care of my fishes and plants while documenting. I didn’t document often so just in case the fish doesn’t get stressed (do they get stressed being taken photos of constantly?) . After 12 days, one of the started showing signs of stress so I spent hours looking up what’s wrong with it. Turns out I overfeed it. The next day it died so I buried it. After that day, the other one also died. However, the second one only started showing signs for a few hours and that was 10 hours before it died. Now, I only have my healthy Vallisneria and my tank. Our rubrics will automatically give me 20% of 50% due to the morality rate. I need to get an A for my science class else I won’t be able to enter (if not, I’d have trouble entering) good colleges. I’m also troubled by the fact that my family isn’t that well-off and getting good grades are all I can do for them right now. I’ve always gotten fairly good grades and this is greatly concerning me right now. I also feel bad for the fishes that I overfeed. I know that this is something viewed as minor but it’s stressing me out more than it should.