Had the same issue with Calculus the first time I took it. But, I could not drop it (not allowed at the U.S. Coast Guard Academy).
Made an ***F***... the only ***F*** I ever made. It felt terrible.
The second time through I eeked out a ***B***. Much better.
Net resultant Calculus avg. (an F is a killer)... ***C-***.
It is ALWAYS better to drop and get the WP (withdraw passing).