hey benn07 personally i would keep chemistry (even though it is demanding) as alot of uni courses in heath require chemistry at a yr 12 level but depending on what you want to do in the future. so now business or food.... having never done either of them i would say choose which you prefer but from friends experiences business is more apparently more demanding. Ultimately i think if you rule out continuing study at uni relating to Chemistry DROP IT ASAP it is a subject you just have to work hard for! that would be the best choice .
btw i do chem, physics, general maths, adv english, ext eng and religion 1U dropped Economics (unfortunatly) but it was to much work for a subject i wouldnt need in the future for uni as you can prob see i want to do science/english