Have you tried the goo.jp thesaurus? I find it quite lifesaving when I'm confused about things. Teachers are also of great help. TBH small differences are where I make a lot of mistakes since 99% of the time they're not important enough to change the meaning. A lot of them are related to level so formality more than meaning, so you do get odd looks when you drop something 古い・硬い, but that's about it.
JOI also has private lessons, btw. They're really flexible about what to cover during lessons. (another trick is to use unpopular timezones like 5am GMT, when you can catch teachers 1-on-1 during otherwise group lessons, and then basically bombard them with everything that's ever bothered you since the lesson will be over in 10-15 minutes)
JOI also has private lessons, btw. They're really flexible about what to cover during lessons. (another trick is to use unpopular timezones like 5am GMT, when you can catch teachers 1-on-1 during otherwise group lessons, and then basically bombard them with everything that's ever bothered you since the lesson will be over in 10-15 minutes)


