because i don't want to run the risk of studying extremely hard for another 3 years and then still not getting into medicine. And if i don't get into medicine from biomed i'd have no idea of what i'd go into
Biomedical engineering, teaching, physiotherapy, dentistry, speech pathology, optometry, JD...etc.
There is no shortage of pathways for you to go, if you can't find something else in that list that you would be interested in, I don't think you're opening your eyes enough.
And oh, I don't understand, so you expect to get into medicine from Year 12 but you aren't willing to take the risk, effort and time to do graduate medicine, well, that truly shows your dedication to wanting to do medicine, and I'd like to see you say, at your interview, when posed with the question, "if you don't get into medicine what will you do" - "i will go into commerce/law because i don't want to take the risk of doing graduate medicine".