I've learned English for over 10 years, having many different English tests. Initially, I couldn't imagine that I did better than some English speakers in the exams. After teaching some of my foreign friends, I realized that there were much more rules in Chinese than I'd ever thought. Therefore, I began to understand why many native speakers couldn't get a full or even just better credit in their domain.
So don't be frustrated when you getting a bad score in TOCFL, it is also hard for the Chinese native speakers! Hope you can build up some confidence after watching these videos.