Take the F?

so i have a problem w/ school. i have this cl that i wnat to drop, but i don't know if its too late. i'm totally gone from that cl, i don't know anything, totally bomb on da first test, and might do the same on the next, cuz i've been so lost. i can't afford to fail. all the dates to withdraw, and get refunds are ped, so i don't know. a reason i don't know if i can drop it is, i get a grant, and i need a certain amount of credit for that grant. i dont' want it to mess up my aid, or i guess i'm asking will it mess up aid. we're almost half done w/ the semester.....idk....so confused