You know you have spent enough time and effort on the CMA exam and you still failed. So the next possible reason is that you didn’t manage to understand the concepts afterall. Is the CPA review materials too general, or is it too complicated to understand?
My earlier suggestion was to go back to your text book and read, but I realize this doesn’t work too well among my readers. Passive studying (reviewing and reading) can only take you to a certain level. To really understand the concepts AND able to apply concepts in practice, you need active studying — working on practice questions many times until the concepts naturally come to you when you read a question.
This means that you can work on the weaker areas in your existing practice questions. If you believe you need a different set, I recommend Exammatrix as their adaptive learning technology. It is especially useful for those who look for supplement instead of another full review course.