As usual for the CFAT, get your good night's sleep, no caffeine, make sure you aren't sick, and since you can't study for it, practice.
Look over fractions, (Multiplying, Dividing, subtraction and addition), long division and multiplication with full work shown. Regular arithmetic, etc... You can find a lot of the study material by the internet. I practiced it quite a bit, and I scored just under officer and, at the time, I had not finished Grade 10 when I wrote the CFAT, meaning I didn't have the required education for my chosen position.
I wrote the CFAT when I had a throat infection (I thought it was just a cold), so my nose was running, my head felt like Arizona, throat sore and I had no tissues. (Sorry armies). You should have a better time writing it than I did.
After that is done, just start exercising. Try doing push ups every morning, set a goal, practice and achieve that goal. Find motivation as well, as that will help you push further when you feel like giving up. Good luck!