Drill questions, drill prelim papers. Why I say so is because u
can do most of the MCQ, which likely suggests you understood the
concepts. But you struggled at structured questions, which means
you do not really know what are the key words to use, not the
actual way to present your answers.
Drilling with the solutions beside you helps you to focus
directly on learning how to explain. Reading your notes and
textbooks will offer little help as they have usually too many
words that are inconsequential and useless to your explanation
based questions.
If you can finish the TYS 3 times and 1 full set of 2009 prelim
papers, you will get minimum a B3.
The method is there and proven. The remaining question lies in
whether you are disciplined enough to do so, not only for physics,
but also for maths.
Hope this helps, and good luck! :)