I'm thinking of my grades suffering because of stomach issues
What's causing your stomach problems, do you have an idea?
I've been watching too much anime and I haven't stabilized my stomach yet.
It seems that you are aware of the source of your stomach problems, so you should prioritze your grades and watch less anime. If you need help with your stomach problems you should seek medical attention before your stomach problems worsen.
Nah, I have to watch this seasonal anime otherwise my heart will be broken.
The anime will still be there once you have finished your studies and improve your grade. I do hope you don't binge-watch that anime and try to just watch one episode a day so that you wouldn't have any stomach issues.