I agree with @happy1, if you fail the course, it may seem like you stopped trying senior year, even if that isn’t the case. I think your best option is to switch out into an easier course. I know that my school offers a course called Business Calculus, which is basically the easier, more slowed-down version of calculus which would show that you technically did calculus, but your grade would be a lot better.
If there isn’t a similar option at your school, then I think your best option is to switch to an easier math, even if its not calculus, like statistics.
Try talking to your teacher and see whether you can stay after school a couple days a week to recover from this or whether you can do any makeup work. If you explain your situation, I’m sure they’ll be understanding!
Good luck!