Struggling to remember readings

If the Wanikani mnemonics don’t help, you can always try making up your own, or borrowing some from other users (maybe check out the Community Mnemonics userscript) or another site (I find to have very helpful, though often crude, mnemonics).

I also agree with @voxxys that your best bet long-term is to further expose yourself to more Japanese. To start with, maybe check out some of these free online books for beginners which have pronunciation written over kanji as furigana and also have an audio track of someone reading the book.

Also, going forward, I find the “Phonetic-Semantic Composition Script” helps me recognize patterns in pronunciation. Things like: most of the Kanji with 方 as part of them are pronounced ほう or ぼう.