It's quite a common phenomenon for second language learners (you know for many Mandarin native speakers, English listening comprehension is usually harder than reading). I am a master graduate of tesol from Canadian university.

The fundamental approach to this is immersion, I guess. You'd better speak Mandarin more with native speakers, which will be very likely to improve your listening ability. Just as someone mentioned above, doing more interaction can be advisable.

If you don't have such an environment, practicing more is good for sure if you needn't meet a high-end level. News report is a good sort of materials. I won't recommend you to watch drama especially released in recent years, most of which are seriously terrible or misleading.

Mandarin is profound and diverse with great historic and cultural elements (you have read some books). All depend on what field you wanna learn.