I don't know if I can do this

I did hit a wall in WaniKani around level 30 as well. My solution was to slow down by doing only 12 lessons a day (3 kanji, 9 vocab) using the Lesson Filter script. Fewer lessons = fewer reviews = better accuracy. It definitely won’t fix all issues, but it helped me a lot. I don’t know if that suggestion is relevant to you, and I don’t have any suggestions regarding reviews or general study approaches. Honestly, I never really fixed my leech issue in WaniKani and my review percentage got worse as I reached higher levels.