You need to stop when you dont play your best game, when You became bored with a game and uncomfortable to play
I agree with you. It's always good, before starting a game, put the limit of how much you can lose that day and follow this planning. Weight loss and weight loss.Play a specific set of buyins or MTTs and play for a set amount of hours. If you like to play 2-3 $1/$2nlhe or 2-3 MTTs a day play that. But if you go bust at any don't buy back in. Set limits on yourself like a budget. Say to yourself I will only play $100 worth of my bankroll today and no more. When you are running bad, limiting yourself will help keep the loses under control. Or go down limits if you are running bad to help ease the loses. Always set limits though. Don't try to recoup.