Some schools have equity type scholarships and such, maybe look into some of those. You're aiming to get pretty high so make sure that you look into things such as EAS which can help give you a bit of help, it seems like you deserve it. As far as what school to apply for, IMO apply for all of them, if you only apply to one or two your chances are a lot less.
Also, you need to determine if a change of environment will negatively affect your motivation which you clearly have lots of. I changed schools for similar reasons to you and found that I hated my new school and found it really hard to do my work because I couldn't be bothered.
Why not try looking up Chemistry notes on a site like csu.hsconline.edu.au, I basically taught myself HSC chem from here. It's great and can really explain topics. Don't forget that if you get stuck, you can post up here and we'll give answering a go. There's some pretty cluey people about.
In the end however it's up to you. If you're motivated and driven (which you seem to be) you'll get there, just don't be too proud to accept a helping hand when it's offered.
As far as goal setting goes, you seem to have a big goal in mind but at times big far away goals can be a bit hard to help sustain you're drive and motivation. Instead, keep your big goal but break it down into little bits. Aim to understand a topic or complete a practise essay on the weekend, try to break it down into little bits which are so much more manageable to avoid feeling overwhelmed.
Good luck!