Have you ever been in a situation where you said something that affected someone but you had no idea and then a while later theh blew up at you saying you always say stuff like that? Apparently, i said something insensitive about my friend's dog, but i did it with good intentions and the hours later when i mentioned so ethjng related to the dog she started hitting me and yelling at me and crying and i have no idea what was so bad in what i said

It's best to ask why they were hurt by what you said and then once they tell you why, talk through it. If it's a reasonable explanation just say you won't do it again. If it isn't, then talk through it some more until it is.