While your numbers are a dream, if your ECs are in fact light, you may not be as competitive as your numbers suggest. There might be more than you mention though, so assuming there is:
Completing the whole AMCAS application process is an enormous undertaking that will probably take you 100+ hours. Doing all that to apply to just one school, and then, as an international student, having to worry about how you will pay for it -- that's generally a pretty big hurdle... Then there's the girlfriend and what country you want to live in now, live in later, work in - etc.
It's easy to let your goals be swayed by an unexpectedly strong result and the new opportunities that opens up, so step back and really ask yourself if it's your heart or your ego talking, and take a good look at what it is you really want. Were you focused on Melbourne because you assumed Yale was impossible? Or were you focused on Melbourne because that's what you wanted?
If you do decide to move forward with an AMCAS application cycle, look first at the money and how you'd be able to pay for it. There's a forum here for int'l students and I'd read deeply over there. Once that hurdle has been cleared, then look at what schools even accept int'l students, and which of those you'd love to attend. If it's only the one, then - wow, that's a lot of work for one tiny chance. And what about the Canadian schools? I know they're really hard to get into, but you seem like a really strong candidate...?