i hate my job

so i work at this cafe and it's honestly the worst. like everyone is super rude to me all day long, cus apparently serving coffee turns people into total monsters or something. but yea so today some customer literally told me that they wanted their drink extra hot but with less water cus they were too lazy to say just make me a stronger brew. and i'm like ok im gonna go back there and throw in more grounds but do it super slooowwwwllllyyyyy so this person sits there for what feels like forever, then gets pissed when the drink takes longer than usual cuz i'm putting extra care into making them pay for their own selfish request. feel bad? should i try to be a better sport about stuff? or is it normal to kinda take petty little revenge on customers who treat me badly?