Just interjecting with my 2 yen here... What really helped me with my Japanese study was going to a class regularly. There was a class in my little corner of the inaka for gaikokujin to study Japanese, and it was super-cheap and affordable too. I think it was 2500 yen a month actually! I'm telling you, super-cheap. They did it through the city kyouiku-iinkai and also had a weekend class at the local community center, so maybe your local BOE may have something similar? It'd be worth looking into in my opinion, for two reasons.

First, the purpose of the class I took was to prepare us for the JLPT. We had lessons that followed exactly what was going to be on the test. We did long essay readings, kanji, listening practice, the whole shebang -- everything that appears on the test. So when it came time to take 2-kyuu, I was very well prepared. And I passed, thanks to Ikemizu-sensei! d(^_^)b Secondly, having a weekly class that I had to show up and be prepared for was a good way to motivate myself to study and complete the homework assignments. Sure, I still procrastinated sometimes and all that, but having a set schedule and knowing you're gonna have to be at that class makes it easier to set aside time to get the studying and work done. This is probably all the same stuff you tell your English students, isn't it (^_-)