Other than being inexperienced, I can’t say there is anything wrong with your game play. First off, many players have found winning with the Allies to be difficult due to the seemingly easy task a good (or even inexperienced) Japanese player has of gaining the 22 VP’s. There are two things you can do. I have posted a link below to a webpage with the FAQ’s. This will answer many questions you may have on the rules, and will clarify others. Most importantly it has a slightly modified set-up to help balance the game. Avalon Hill admits they may have layed an egg with the VP’s, so make the Jap’s have to gain more than 22, somewhere between 24-28.
Secondly,if you wish not to mess with the rules and set-up, I suggest looking under strategies on this website. Under Axis and Allies Pacific you will find nearly a dozen excellent strategies written by Saburo S. Covering both Axis and an Allied strategies.
This is, IMO, the best variant of the Original. It is critical to continue playing it. The more experience you have, the more options you will find yourself finding, and thus the more balance you will find exists in this game.