What to do when a child hits you?

My daughter was screaming at me (1st grader). I told her if she continued to scream I would close her door. She then went up to me and hit me in my stomach. I then closed her door and said hitting isn't nice.

I tried talking to her about 15 min later about how hitting isnt nice and how would she like it if I hit her? She said she wouldn't and that would be bad. I said why do it to me then? She said because that's what I do when I'm mad at you. She then kept screaming so I took away outside privileges and went outside with her sister. I told her she could have gone outside if she calmed down and apologized, but she refused.

She does not seem to care the hitting hurt me or how stressful her meltdown was when I've been sick with a headache all day. What do I do from here?