Why Did I Do That?

So I've spent the last 36 hours or so being sick. Nothing too terrible, just a little virus it seems. I'm certain I'll be 100% by morning, ready to face another week. My kids are old enough now to kinda take care of themselves. My oldest daughter, the little mother, very sweetly made sure her little sisters had the things they couldn't reach or take care of themselves and then repeatedly checked on me, asking if I was hungry or needed anything to drink. Such a princess she is. She made lunch for everyone. She sat near me a lot, as she often does. She's a mamas girl and I mostly love it. She's very mild mannered and easy to get along with, she's got a good sense of humor, she's extremely helpful and just wants so much to learn to do all the "domestic" stuff. She will often quietly do a little chore that I have a hard time keeping up with, without being asked or expecting any reward or privilege in return. She likes to be home, doesn't always want to go do things if I'm not going to go also. She's just a sweetheart, and I love her uncontrollably. And she took care of me all day. And then at bed time, I wasn't happy with how clean her room was and I yelled at her. And she cried. I hurt her feelings. I can't help but think that she was thinking. "I took care of you all day, why are you mad at me about this". I know that's what I'm thinking. So now it's late, my guilt is nagging at me, and she is sound asleep, as she should be, so I can't apologize to her. I failed again. I got angry about something dumb, unimportant. I never thought I'd be that mom who hurt her kids feelings over dumb, unimportant things. But I do, a lot I think. I hope that's not what they remember about me when they are grown. I hope I am able to show them that they are treasured and adored and valuable and special and more important than a messy room.