I love my wife. But she is so sensitive to everything I say.?

I don't know what to do. I feel like I have to walk on egg shells with her/ I can't "kid" with her. I can't be myself. Just like tonight. We were putting together an excersize bike that she bought for me. She wanted to know about what she was suppose to do with a washer and a bolt. I told her to put the washer on the bolt,line up the hole and screw it in. She said, One more word out of you,and you will be doing this yourself.

Ticked me off a little. I said OK, I can do it in about 5 min. She got up and left. I put it together by myself.

But that's not all. The other day, she got upset because while I was driving behind her in my truck and didn't see her waving at me through her tinted back glass of her truck. She said I didn't know what romance was. I was like, What's that got to do with it? I couldn't see you. It's crap like this all the time. She is 44 and I'm 52. It seems to me we are a little to old for this.