I think it would be a good idea to work out a schedule for doing your reviews and stick to it as much as possible if you haven’t already done that. You should only need to be doing reviews a 2-3 times a day. If you’re trying to go through WaniKani fast you can expect upwards of 100 reviews a day on average.
A schedule would look something like this.
8:00AM - do reviews and lessons
12:00PM - do reviews for new apprentice items from earlier lessons
8:00PM - do any remaining reviews
If a midday review time doesn’t work for you, this way could also work
6:00AM - do reviews
6:00PM - do lessons
10:00PM - do reviews
Setting up a schedule like this will make sure you are doing the first apprentice reviews as early as possible and help get the new items stuck in your head. I would also recommend spacing out lessons so you’re doing some every day. That way you don’t overwhelm your brain with new information on a single day and you spread the reviews out more through the week. Around 20 lessons a day would keep you near or at full speed.
Edit: Also if you haven’t yet read it. I recommend reading The Ultimate Guide for WK. You’ll find lots of useful information in it.