50 tourney in one day is a lot. Too many IMHO. Shows an impatience that will destroy you. Changing to cash could actually be worse, as you can reload faster than you can find another tourney to get into.
Relax, play less, and play better.
If you have an uncontrollable urge to play that hard, use play money games to vent your anger.
If that doesn't calm you down, seek medical attention.
He´s not talking about Mtts. S&G´s takes about 30min avg (turbos, hypers take less time), so 50 games/day is really not a huge number if are multitabling.
To Pokgai, you mention 16% roi before your bad day, what is the example on this roi? (# of games played before). And mention $100 down, so if are playing avg buyin of $4.5 you lose more than 22 buyins.
I think you should set a stop-loss number. I mean 10-20 buyins down on S&G´s is not that uncommon (that´s why BR management suggest 50-100 buyins, even 200bi for larger fields) but if after that you get on tilt then the amount will increase a lot more, so having a stop-loss amount set (like 10-15 or w/e) then when you reach that amount just stop for the day and save you to blow your BR.
When this things happen the best is to just stop for that day and try to get on your feet next day, worst thing that most people do is keep playing trying to get back loses, lose more get on tilt and keep losing more. Take a break for a day or two and if still keep losing that bad need to review HH´s because maybe tilt and leaks could be helping to lose more.
Hope things work better soon, cheers.
Edit: and what Arjonius and Micro suggest is true. if see are doing that bad then cut the $6 games and stay just with the $3´s, even go down to $1.5´s if this mean lose less, also moving down can help if start to win again/increase your motivation/good feeling again, because the hard part is how you face the following time after the beats. After things calm down then you can move up again if BR let you.