What is your experience with learning Japanese grammar and reading native Japanese material? By level 16, you’ve learned a lot of vocabulary that’s actually fairly common. If you’re reading native material, you’ll come across the vocabulary and various situations, and it will become easier to recall.
To that end, I always recommend checking out the WaniKani community book clubs, especially the Absolute Beginner Book Club for first-time readers.
It’s best to learn some basic grammar first (if you haven’t yet), then you get to dive into reading your first work of native Japanese material (again, if you haven’t already). That gets your foot into the door on seeing all kinds of familiar vocabulary (while learning even more).