Just a little advice, in the gouge section, there's a link to someone's website (Air Force) that actually typed all of the ELO's and the answers. My wife printed all of them off, cut them into strips and pasted them onto note cards for me. It saved me a LOT of time and made things much easier for me. Naturally, I checked the answers, just to ensure they were still correct, and also added the info I got from the reviews the instructors gave. I did very well on almost all of the tests (made an 88% on the engines, but other than that a 94% was the lowest grade -- with two 100's). I would go through each notecard and memorize the answer. Once I had those memorized, the night before the test, I would read through everything I highlighted in the pub and take the practice tests (I never wrote the answers in the book -- kept me from trying to cheat). I would usually study for an hour in the morning before class too. It's just a technique I used -- maybe you've found something easier that'll work for you. Nav will just take a whole lot of elbow grease. You must practice as much as possible.
There's a light at the end of the tunnel! The last couple of weeks of API are awesome! Ground school at Primary isn't too awfully bad either! I haven't studied as hard as I did at API. And the Turbo Weenie is a blast to fly! FWIW, I started API in November and graduated December -- so it wasn't that long ago for me.
Good luck!