fight or flight? I flew

I've never had a huge argument with my sister except for that time she hit me with a mop and I sucker punched her chest, but a week ago she and I got into a huge argument, we we're both exhausted because we had to look after our mother who just got out of the hospital that time and she had to file all the paper works and I did all the chores in the house. And when things got out of hand I just cried while she yelled at me. We were both just exhausted and had no clue of what we were doing. I left the house and went to my cousin. We said sorry the day after, but until now I'm still at my cousin's.