Ben,I totally support what Lee says.
Try not to think of the exams as a load of old tosh that needs to be learned and passed parrot fashion,some of the info in all the subjects could save your life.
My method was to read the Thom books cover to cover and then do the Q&A at the end of each section until I knew the subject ,also had a one to one ground school instructor for an hour or so for each subject,at £15 /hour.
I never used the confuser.
Failed a couple first time but can't remember which ones now,I think I got 70% for the fails.
As soon as I had finished and passed one subject I immediately moved on to the next.
The most important thing is your mindset,if you think "why am I learning all this stuff,I just want to be out there flying" it will make it very hard work.
All the time I was doing the exams I was thinking " A lot of this is really useful,some maybe not so useful,but I need to learn all this and get the exams if I want a pilots licence"
I did them all and I was 63 last week,and believe me it is harder to learn stuff as you get older.
Anyway good luck with the studies.
Lister
