If you are surprised by how low your listening score is compared to practice exams, then you need to spend more time doing "real world" listening practice. Things like news broadcasts, college lectures on YouTube... even films. I find that the practice exams included with study books sometimes give students a false sense of security.
It is entirely possible to increase your overall score by 14 points in two months, but you'll have to study a lot. Keep at it!
Edit: I just noticed that this was a necro thread. The original post is two years old. Whoops!
:TOEFLresources.com: Step-by-step guides to the test and a free essay evaluation service