For me I can stop whenever I want, Usually I will set an amount of cash I am willing to lose from my bankroll and if I reach that limit, I will shut my Poker site down and take a break, sometimes as long as a day or two before I get back into it, Seriously!
Poker has to be fun, and if I am not enjoying my sessions at the tables, I will quit regardless of how much I am up or down, I did hit the tables really heavy during the first lock-down, because I set myself a target of doubling my bankroll before Christmas. which I did quite easily, but you have to have some kind of driving force to be able to play as much as I did.
Likewise when I was playing Live I was determined to make the top 4 places in the league so that I would qualify for the Regional Final's played in Manchester, and then hopefully make the top ten places in that tournament to qualify for the National Final.
Playing on-line honed my game play so I was ready for the weekly league game, although playing "Live" was different than playing On-line, but you can adapt to the differences, and overcome them.
I got so good in League games, I qualified for the Regional Finals regularly and once bet someone that I would finish in 1st place adding a trophy to my collection, which I did twice in two consecutive season's.
Poker is fun and you have to control your bankroll in order for the fun to continue, There is no fun losing money hand over fist, it just becomes an exspensive hobby, I can honestly say On-line Poker has never cost me a penny, as I have never made a deposit, and I know when to Stop!
When the fun Stops, STOP!