If you have principles, they don’t change just because you are personally affected by something. If they do change, it means you probably didn’t have principles to begin with, but were just following your feelings; a convenience.
Or, maybe you realized your previously held principles were wrong. It happens.
Or, maybe you have reasons why you felt the need to abandon your principles. I suppose that happens, too. The only reasons for that I can see involve a desire to do something your principles told you is wrong, and the desire to do it anyway was stronger than your attachment to your principles.
I recently saw a person publicly declare he is rejecting the Zero Aggression Principle (ZAP) after years of following it. The reason: Someone had insulted his girlfriend and he decided that the ZAP was inconvenient and “pacifist” because it informed him that using violence against the insulter would be something he didn’t have a right to do. He didn’t like this and started posting links claiming that words cause real harm.
He totally missed what the ZAP is.
I have always said, if you feel a need to do something you have no right to do, go ahead and do it. And live with the consequences.
If you reject the ZAP, my question to you is this: Who do you want to attack without feeling bad about yourself?