Why does my wife always yell at me?

My wife stays at home with the kids. She always yells at me for every little thing. Like yesterday in the morning I took a baggie with three muffins in them that were sitting there on the counter and she says sarcastically, "who are you going to share those with" and I said, "oh, I just grabbed them". But fshe said it in a very rude way. And then, when I spent three hours trying to fix our kitchen lights (they were damaged by lightening that must have struck hard in the area) I couldn't fix it and then I called an electrician to come out and when she finds out, she starts yelling at me that they are too expensive and then she calls someone else. And then last night, on the way home from work, I had to stop and get gas and got some videos for the kids to watch and I called her to let her know I was running a bit late and she starts screaming at me again. I am just so tired of being yelled at all the time. And then she gets mad at me because she says I don't say "I love you" enoug