Oh, I am also learning a difficult language (Polish).
I did find a couple of things that can be useful:
Buy a dictionary Japanese - (your native tongue), use it to look for unknown words, do not use your phone, alternatively buy a Japanese dictionary and search for the word meaning.
Maybe you already are, but opt for language classes with a medium size group (less than 8 preferably).
In my case my girlfriend is Polish so I ask her from time to time for some specific sentences I may use, if this is not your case, I think a few Preply lessons could help with a native speaker.
Memes, for some reason I picked up on the language faster through memes, if you are already struggling it helps to “relax” and check for something on the phone, also the words used there are the ones that natives actually use.
Last one is, use your medication, I have 2 pills, one that lasts 5-7 hours and one that acts immediately after taking it, but last maximum 2 hours.
Oh, I am also learning a difficult language (Polish).
I did find a couple of things that can be useful:
Happy learning 😇