Treat it as a life-time investment (US$200K+ including opportunity cost) - try as many time as you can. It took me six years studying English and raise TOEFL from 217 to 280. I am confident you can do it in much shorter time.
To practice listening, try listen to online radio (such as NPR), rent American drama DVD (such as Trump's The Apprentice) or watch free online TV (eg. ESPN, Animal Planet, Disney (Teen Drama)) to learn American idioms ;-)
Download TUV Player, connect broadband, and ... done.
http://www.tvunetworks.com/downloads/index.htm
祝打T成功 !