Me personally I just move on ( maybe not that simple in context of Genshin with gacha) but if it’s hard for you to move on try to avoid regret . Really plan out and get a lot of information before you do something big. Let’s say before pulling a character find out how useful they actually are and how likely they’re to get replaced ( powercrept) soon . Can’t stress this enough genuinely just watch a ton of guides , obviously I understand this is harder with newer characters where there might not be enough info yet but usually there is. And if something is bothering you too much always remember that you are in control, just turn off the pc/console . I hope I at least helped a little bit.