I'm not sure which aptitude tests you're referring to, but my first thought is what you are being compared against? Is your score from attempting the test once or twice being compared against people who have done it dozens of times or even some arbitrary number made up by the website owner?
If you are curious as to areas you need to focus on, try something like the aptitude testing offered by the Honourable Company of air Pilots. Use the feedback from that to think of areas to work on. It sounds like you'll have a bit of time to work on it.
Someone once said that anyone can be taught to fly, it's just whether they can be taught to fly in budget. So a natural person may be able to do it in minimum hours and others may need a little more time, so budget a little extra to allow for some additional training.