I will second what some one else said...
Take a job, get some cash, and study part time the exams, and when you reach the stage to take the CPL and IR tests you could quit, having made some money, or keep going part time and make some more...
As for aptitude, stressing about it makes it worse, i did better in my first one than my second one, by a fair. The test are to see if you can cope with the different aspects of becoming a professional pilot, they are not designed to trick you in anyway.
Maths is similar to what a 15/16 year old does at a C level at the most, the tests are basic, a little physics in the one i did. However, there is a trick, only answer if you know the answer, if you dont know it, dont attempt it at all, i was told this by an interviewer some time back.
There is nothing hard in the ATPL Exams, its more to do with the fact the ammount you have to learn in such a short space, its all multi choice, and to be honest, I have a Mech Eng degree and no technical questions caught me out at all, so not sure why they did for the other poster with a physics degree.
I might get slated for this, but its like taking a DVLA exam, study from a book, and turn up and sit a multi choice exam, people might say its different, but i can see how.
Strong x-wind landings, windshear, inflight emergencies, now thats the harder/skilled part about flying in my book.