I actually only studied for about 6 weeks... maybe a bit less since I definitely took days off of studying. I'm also working full-time in a hospital setting as a part of a yearlong internship. I wouldn't recommend studying for more than 8 weeks, everything I've read said it isn't any more helpful.
I took a 2 day Therapy Ed course, and then studied from the manual for that course and also from the o'sullivan book. I read each one cover to cover, made notecards, wrote stuff I didn't know down in notebooks. I took all three o'sullivan practice tests, got low 60s on 2 and a 70 on the 3rd. I borrowed the Giles practice test CD from a classmate and took 2 of those practice tests. Those were a bit "easier" and I got mid 70s on those. My school was amazing and gifted us the PEAT exams. I didn't do great on the first one but got an 80 on the second. I gave myself 4 days before the exam to get my nerves calm, sleep in, study lightly and just feel prepared. The biggest thing the prep course taught me was that the vast majority of people who don't pass, psych themselves out. So I prepared myself mentally, and I think that helped the most!
On test day, I got a good night's sleep. I reviewed a couple notecards. I read each question twice and "marked" any questions that i had any doubt on to review a third time. I felt completely awful walking out of that test, certain I had just completely screwed up. But turns out the preparation paid off!
I wish you all luck! If you didn't pass this time around, give yourself a week, maybe more to just relax. Don't throw yourself right back into the books. You need to give your brain a break!