I'll get right to it. Nothing in life is clear-cut. There are bound to be curveballs along the way, and part of growing up is learning how to deal with it. There will be obstacles to help you rise, you just need to know how to power through them.
With that said, "powering through" doesn't always mean buckling down and running into the proverbial storm. Sometimes, it means taking some time for yourself. This is especially important regarding our mental and physical health. So often, our first instinct upon getting sick is thinking, "this is inconvenient." While it may seem that way, that isn't always the case.
NEWS FLASH: Assignments can wait. Tests can be rescheduled. Professors understand that you're only human, and 95% of the time, they will offer an alternative date to submit something.
What's important is that you feel better.
No grade is worth sacrificing your health, so if you need to take a day or two off, then do it. You might be delayed a bit afterward, but that's better than trying to focus while sick.
Remember, we're all only human.
We're doing our best.
Sometimes, our "best" means stepping to the side for a bit. And that's perfectly fine.