There are a bunch of factors that will change how often you mark your cards as 'Incorrect' (different students, different languages, different studying styles, and different language levels, to name a few). And the number of cards you mark as 'Incorrect' will influence how many cards show up each day for reviews.
My personal tendency is to see around 150 cards (including my 30 new) each day when I want to spend a solid 30 minutes each day on a language. If you're seeing 200/day, and it's feeling overwhelming, then you should definitely turn the new cards/day setting down, perhaps to 20 or 15, and spend some time at that level until you figure out whether you feel comfortable there or not. If it's still uncomfortable, turn it down even further. There are no rules in terms of how many you "should" be doing each day. I'm currently doing 10/day for my own Japanese, because I just don't have a lot of time, and I don't want my Japanese to feel so overwhelming that I stop studying. I may even turn it down to 5/day at some point. So don't feel pressured to stick to some study schedule that isn't working for you! As long as you can maintain some sort of regular study habit, you'll keep moving towards your fluency goals.