I know that some Doms/Dommes call themselves god or goddess but in the end we´re all humans. We have good days and we have bad days, on bad days frustration can sometimes push you to some bad behaviour. It´s easy to lash out at subs, but a professional Dom/Domme shouldn´t do such a thing. Well no Dom/Domme should do such a thing!
But isn´t BDSM a way of lashing out? I think if you see it like that then you´re not really getting it, because if BDSM was just a way of getting rid of your frustration then that would be a sad thing. It seems easy to just lash out, you´ll feel better for a moment and your sub might not even mind. But it´s wrong, that shouldn´t be your motivation to dominate! If you have a bad day then you might want to think about going through with your session, if you do decide to keep going then try to stay calm and don´t let your frustration get the best of you. I´d always recommend to keep personal affairs out of a session with a sub, especially when you´re a professionale Dom/Domme!
When you´re in a relationship with a Dom/Domme or sub then it´s not a suprise that you can get in a fight, but once again try to keep personal drama out of a session. It´s better to talk about things than reacting like a child and holding a grudge, maybe it feels good for a moment but this isn´t how a Dom/Domme should behave! If you want to be respected then it´s important that you give others respect. It seems simple but I´ve seen this go wrong multiple times.
So what can you do against this? Have some clear rules, these rules should protect you and your sub. This way you keep personal drama out of the sessions and have a good and fun experience for you both! Once again this seems simple, but it´s important that you´re both clear about this. Just pretending you´re ok with something is a good root for frustration, which is something you might want to avoid. If you have anger issues then you might want to think about being a Dom/Domme, because if the slightest thing can set you off then it might create an unwanted situation during a session. But talking about these things help, communication is important in a D/s relationship.