>>535843103
NTA but VN + Texthooker + Anki works well.
Doesn't need to be a VN necessarily but read literally anything Japanese, extract every last sentence, figure out the meaning and repeat them until you've read it and grasped it entirely.
Collect Kanji and sentences you don't understand, build a flashcard deck in Anki and review them until they're drilled in your head.

You would need to quickly crash course Kana to start but you can quite literally memorize those under 24 hours.
It's also helpful to keep a resource for basic grammar bookmarked.

You can do this under 3 months and never need a translation for a doujin to wank your willy to again anon-chan, what are you waiting for? *smooch*