I can speak on this from experience. I hated calc. I failed calc 1 once and dropped out 3 times. Calc 2 and 3 were a breeze. Ended up being an engineer. :dunno:
Anyway... From my experience, as long as you start out the semester as a full time student, you can drop to four credits without problem. I did this a couple of times. I was going through a rough patch in college trying to choose a major, my younger brother passed away, women issues, depression, etc. For two semesters, I started at 14 credits and by the end, I was at 4 one semester and 8 the other.
It's much easier to explain a W on your transcripts than an F and a W doesn't hurt your GPA as much as an F would. JMHO.