Clearly the March exam does not require you to learn all the FA 2016 changes and from what you say by doing March you will only need to be studying one subject instead of two! Your problem as noted before is that you still lack the fundamental knowledge required to pass the exam and have been attempting questions and getting into problems as a result. Put the work in now and sit the March exam would be my advice. The lectures for June will be available by the end of February / early March