Then I would recommend that you slow down. Continue with reviews, but take a break from doing lessons until you’re comfortable with the load of reviews you’re doing. When you’re ready to do lessons again, do a set number like 10 items per day/week or whatever number you feel comfortable with. There’s also a popular advice about trying to stick to the “rule” of 100 apprentice and 500 guru items at any given time, to set a frame that can guide you to how much you can handle. The numbers doesn’t have to be 100 and 500, try and see what works for you 
You might want to install this script: [Userscript] Expected Daily Reviews
Good luck with your studies! 
