Failed language proficiency twice — what am I doing wrong?

Okay so I've taken the language proficiency exam twice now and I keep scoring in the low 60s when I need at least a 75 to satisfy my employer's requirement. The first time I chalked it up to nerves, but after the second attempt I'm starting to think there's something fundamentally wrong with my approach. I've been just re-reading my old college textbooks and doing some random quizzes I found online.

The listening section absolutely destroys me every time. I freeze up during the audio portions because the speakers talk so fast and use a lot of idiomatic expressions I don't recognize. Someone recommended I try the Language Proficiency Listening Skills practice test on this site to get more comfortable with the format. Has anyone actually used it? Did it help?

I have about 8 weeks before my next attempt. I'm willing to put in an hour or two every day — I just need a solid Language Proficiency study guide or some structured plan. Any exam tips from people who've actually passed would mean a lot right now. I'm honestly starting to panic a little.