Allthough you you started with Aikido (relatively speaking), I would like to point out you do not need to try harder for other people. Do what do because you
like it and enjoy it. Off course you want to do well and do not want to let anyone down, but it is no contest.
How can you prepare? By what you tell I think you already work properly (others say that you make good progress), so keep doing what you are doing and you will be fine. Most importantly, just enjoy especially when taking the test