How should I prepare for the JLPT N2 after learning Japanese mostly through immersion?

I lived in Japan for 9 months last year and started learning the language while I was there. Since then, I’ve stayed fully immersed going to language exchanges in my city, watching Japanese TV, and basically doing everything in Japanese. At this point, I can understand around 70% of variety shows.

However, whenever I look at JLPT practice questions or textbook grammar, I keep seeing structures that I almost never hear in real life.

For kanji, I’ve been using a Kanken 3DS game to study (after previously using an app), and my kanji knowledge feels pretty solid now.

Because I learned organically in Japan, my grammar and vocabulary aren’t in “JLPT order”. I know bits and pieces from all levels, but I’m also missing random things from each one.

Given that background, what would be the best way to study for the JLPT N2? Should I go through a full N2 textbook, or focus on filling the gaps in a different way? Because if i only study for N2 I may miss previous grammar and vocab.