I’m about to be level 13, and started in September. To be fair, I did spend about a month procrastinating actually starting the grind, but you’re going at about the same pace I am.
I think you need to slow down a little. If you’re doing a level every 12ish days like I did for the past few levels, you’re probably going too quickly. Don’t be afraid to take a few days to get some items further down in your review pile. Part of my problem is the stupid small tsu, which I, literally 10 minutes ago, looked up, and it instantly made sense how it works. That stupid small tsu was making me miss many vocab words for no reason. maybe there’s a similar thing for you? Unsure.
The advice others are giving is somewhat helpful, I would say. I did pick up literally hundreds of words and the meaning of many, many phrases from just watching subbed anime over the years even well before I bothered actually trying to learn japanese, and I’ve definitely picked up a lot from both lewd and non lewd(it helps me sleep) JASMR. Watching all the hololive vtuber clips I can definitely helps quite a lot too, I’ll say.
That being said here are definitely things on wanikani you’ll literally never hear used. the “whisper in ear” vocab phrase is particularly useless: the one place you’d think you’d hear that(japanese ASMR), I’ve not heard it.
I think WK will get more rough as the daily reviews pile higher and higher, and I definitely don’t think 12 days per level is really sustainable(even now, I’m starting to see the cracks, this level took me 14 days). I’m of the mind that it’s okay to miss some vocab words right now, especially dumb things like transitive/intransitive(shoutouts to you, bakasu, bakeru, etc. etc.). I figure I’ll eventually start burning some things(I’m still at 0 burned like you), and once those verbs are what’s left, I’ll put effort towards memorizing them.
To be fair, I’ve not even touched grammar at all yet, I’ll probably hit bunpro for that at some point, but I feel there’s better value right now from just getting more vocab words under my belt. It will probably be a little easier to remember those verbs once I’ve actually conjugated them and such too.
If you’re looking for content to consume that matches your WK level, I would recommend https://jpdb.io/ for sure. it’s got lots of premade decks for many types of media, including anime, games, visual novels, movies, etc. etc. In the settings, you can set your WK level, so it won’t show you things you’ll learn through WK and such. You can even make your own decks by pasting in text. at some point when I’m closer to finishing WK, I’ll make heavy use of this feature to learn things like song lyrics. I’ve even toyed with the idea of pulling all the youtube chat from a vtuber’s stream, then using that as a proxy to see if it’ll help me understand what the vtuber themself is talking about. Unsure if that will really work, but I’ll get new kanji and vocab words out of it regardless, so it’ll be fine in the end!
hope my rambling was a little helpful for you, as a fellow relatively new WK user.