parenting the strong-willed six year old

I sometimes wonder if there are no more little Holman's yet because I can't figure out the ones I have!
Parenting is kicking my trash right now.
Miss M is going through a long and tough phase.
I constantly wonder what a six year old has to tantrum and be angry about so much!
And we've created a perfect storm.  I get so frustrated, that I fly off the handle, and I'm screaming, and then by bedtime, we're all crying and upset.

Last week, for example, Miss M screamed through the entire grocery store because she got in trouble for driving the grocery cart into Lulu!
Just another evening in paradise.

I remember when all I heard was how sweet she was.
Now people say things like, she has so much spirit! I know what that means!
I mentioned my concerns to the pediatrician last month and she was encouraging that we were doing the right things. But that we might need some more help.

And so, I'm going to a parenting class in October.
I'm hoping that it gives me more tools for handling her meltdowns.
And some better coping so I don't lose it when she starts losing it!

In the meantime, I've checked out books from the library and I'm venting to my cousin Mae, who seems to live a parallel parenting life to me.  Thank heavens for those that understand.