This exam is tough one (I had the same feeling when I was preparing for the exam), so scoring low on the Standard Tests is not exceptional. It is just an overwhelming number of specs and documents that is covered, some detailed, some briefly. Apart from that there are a lot of "Best Practices" questions where there is no theoretical spec or document to fall back on.
Just continu to review, read and study the questions. Do a bit of hands-on when you still have time (although you won't get a lot of coding questions but just do it for better understanding). It is important that you also do the Last Day Test and review everything there afterwards.
Like I always mentioned on this forum, it is better to use Enthuware, EPractice Lab and MZ's mock exams.
Someone even mentioned that you can use as many mock exams as you can afford.
The exam objective is very broad.