That happens to me now and level 24 was only around 8 months ago for me. 
The thing I’ve found is that you have to read to make any of it stick long term.
I would advise to just keep reading and working through your reviews.
The problem is that most people underestimate both their ability to be disciplined with it and the value of vocab.
The vocab reinforces the kanji in much the same way that reading does: it provides context.
. Especially if you don’t read enough habitually. But when you look up a word on Jisho, which you have burned, you’ll probably remember that word for at least 6 months, during which it will appear again if you immerse enough. No point in going through an SRS from zero with those words. You will get HEAVILY overtested and get pointless reviews.

