You could install these scripts to check how many reviews you’re getting on a daily basis: [Userscript]: WaniKani Ultimate Timeline and [Userscript] Expected Daily Reviews
A bit redundant if you use the first script I linked to, but if you want extra details (like the pink and purple and 
as shown above) on the forecast you can install this one too: [Userscript] Forecast details / critical reviews
Other than that, my only tip would be to not add a large amount of lessons at one time, stick to a set number like 5 or 10 per day/week or whatever you feel comfortable with. If the load of reviews become overwhelming, take a break from doing lessons, which you’re already doing, so good job 
If you feel like the guru pile is too big you could go for a lower number like 400 or 300. See what fits you 
Good luck with your studies, buddy! 
