i really want to do well for amath and bio.

but i'm the type of person who can only concentrate on just one subject and leave the other alone. right now i'm trying my best for amath but i also want to try my best for bio, but it's hard. it's hard when you don't really understand the subject well. i'm scared that i put in all my effort for amath but in the end i still screw it up, hence screwing up both amath and bio. but i really.. need to at least try to do my best for bio.. i have no motivation to do bio at all.