well just in case the holidays doesn't cure your panicky-illness:
* whenever u find that you've forgotten what you've just read, immediately start to take a break. there's no point reading on because it gets worse and worse. however small the break is, it has to be taken...
* explore different methods of studying, but what you're looking for is understanding. you should always walk away learning something new. another thing to look for is a genuine interest in the subject, but trust me, that rarely happens and congrats if it does...
* try to find someone to teach what you've just learnt (whatever that is), to whoever (your friends, or generally anyone who will listen to you). try not to overdo it, cos you'll need friends after the HSC. in return you may be able to get some help in areas you're not familiar with.
* as for definite study plans, never plan too much, cos then you'll never start. your target should be to learn as much as necessary to get you the marks you want, and not something timewise (like 4 hours a day). my friend claims to have done up to 6 hours a day on maths, and then i went to see what he means by that (and i found out it was actually one big waste of time, cos his mind was blank most of the time)
i'll type in more when i think of it...