I’m sitting at 250 a day, one level above you. I remember the drastic shift into more reviews about four levels ago that brought me up to (at the time) 310 a day.
What helped me was to turn off my music, turn on the volume, read the mnemonic for almost anything over five levels old that I missed, and repeat each item vocally at least once (when I’m not doing Wanikani in a public place). Given I’m currently 150 a day less than you and a level higher, it’s definitely possible to cut your reviews down.
It may really suck at first, but if overwhelmed you’ll find taking the initial extra time to keep yourself from perpetually forgetting reviews will save you A LOT of time in the future by not having to keep redoing them. If you feel overwhelmed, put more time into doing your reviews until you’re back down to a manageable amount.