Ah, the Wisteria level with 3 ways to say “boundary”, that was a tough one for me too 
. Congrats for levelling up!
I also struggled with the early 20s, but this was also the time I was pushing myself to read during the Spring read every day challenge. Not only did I get bonus refreshers from seeing kanjis in the wild, which definitely helped with reviews, but reading native material also made me realise how broad some of the kanji meanings were. Broader than the strict WK definitions in many cases. That was a real eye opener.
Previous posters have made great points, I would add that regular reading helped me with WK lessons and reviews very much (plus it’s fun!).
Best of luck with your studies.