I would strongly encourage you do the A level route instead.
Yes A level chemistry is hard, yes its boring, no you will never use it either in vet school or as a vet (and if a client asks me to calculate the moles of something they will be asked to leave) BUT it does make you a competitive applicant.
Your first choice may be RVC, but don't make it your only choice - any vet school is better than no vet school offer.
My application was on the riskier side (not required GCSE grades, resat A levels, years playing around with cows before deciding to be a vet) but it paid off. I certainly wouldn't have risked only applying to one vet school though.