Failure only means you are doing something 
.Just 29 marks away from success. A another sitting will surely help to meet the 300 mark easily.
I'm planning in March and i have same list. After reading your experience it is clear I have to do something more (not sure what is this as of now)
Every experience I read till now have complained about
1. short of time
2. Visio Style question and latency around it
3. Cannot go back
4. Due short of time most of them made best guess.
I'm just wondering if this is how we make design choices in real world and does this exam test such skills. Especially when at least 20-30% questions are answered