Welcome to the dreaded intermediate twilight zone 
…
I’m gonna just point out that you’re in a great place to start using japanese and gradually be over with textbooks and learners material, no need for the cold turkey approach, but still… the balance should turn in favor to more immersion and less textbooks / SRS
In no particular order I would recommend
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Start reading something (there’s a whole secton on that here), simple enough to keep you engaged and hard enough that you struggle a bit.
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Practice listening, use a method, either custom made or a book like this one ( or similar… since it’s somewhat hard to find at a decent price lately).
- Then just jump… star watching a show (slice of life for example with or without jsubs), following Nihongo no mori channel or NHK Kokokoza lessons.
Anyway, it’s more or less what I’m doing… and the so called plateu seems less so every day. It’s no magic trick either, lots of work too, but a huge step over the textbook + WK days 