A little barfy

I know many parents before me have lamented the non-existence of a child rearing manual and I know that my own plea for a cut and dried list of rules is so cliche, but seriously, there has to be an easier way to make sense of this thing called parenting. For the past 2 weeks my sweet, lovable, bright eyed wonder has been missing, lost in a sea of angst and crankiness. I've been blaming it on the time change, the full moon, Friday the 13th (all of which came within 1 day of the other) and her little bit of stubborn sickness that continues to cling to her like a dryer sheet to a flannel blanket. She who used to wake up with a list of questions on her eager tongue now has to be bribed, prodded and yelled out of bed in the morning. She who used to skip around the house singing made-up songs has now a perpetual scowl on her face and I'm out of ideas. I'm tired of yelling, lecturing, explaining, scolding. Is this the 'terrible twos' from which we escaped unscathed? Is it payback? All I know is this is not my sweet beans and I want her back.
And then I think "Did I do this?" Am I too pushy? Too high-strung? Maybe I don't give her enough affection, enough time. There's no answer for me. She doesn't even know why she acts the way she does. But when I wake up to the sound of my child being sick in the next room all my anxiety melts away and I think "She just needs me right now. This is easy." She looks up at me with big, sad, wet eyes and says "Mom, I'm just a little barfy today" and all I want to do is fold her up in my arms. I know how to do that. I know how to comfort. It's the rest I'm feeling insecure about.