I took 13 months to finish the lot (also with BGS). From memory, around 6 months for mod 1, a couple of months off, then 5 months for mod 2.
What you describe is perfectly normal. Read the section, do the progress test, get over 75%, move on. I forgot much of it within hours of doing the test, but don’t worry, it’s all tucked away in long-term memory. The brush-up courses are very intense (mod 1 in particular) so expect to put the rest of your life on hold for a few weeks, but they are
extremely effective. Alex has an excellent team there, and they are very good at what they do. Trust me, by the end of the 2nd week, you’ll be dreaming exam questions in your sleep. Literally.
As for revision, I allowed a month between finishing mod 1 and going to Bristol, which I used to go over the subjects I’d found hardest (gyros and long-range plotting). It helped a bit, as I felt more prepared psychologically, but with hindsight I’m not sure it was that necessary. For mod 2, I went straight from progress tests to the school, and didn’t feel any less prepared.
However you do it, it’s a long hard slog - wait till you get to law questions about the size of registration letters on hot air balloons
- but look on the bright side – once they’re done, you can get on with the flying!