And I don't feel like venting to my husband..

I am overwhelmed right now.
I have no desire to do anything or talk to anyone. Actually, locking myself in my room with some water, chocolate, computer, and a few books seems ideal to me.
I want a vacation from everyday life.
I don't come close to even feeling like Superwoman.
I find myself getting extremely short and easily irritated with Shannon. If she throws one more outburst or tells me "no" one more time, I'm handing the kids over to Warren and shutting myself out for an hour or two.
I'm so irritated that I can't seem to keep up with just the basic housework. Or today for example, the garbage bag was completely full. I walked into the kitchen and saw it overflowing. Instead of getting out another bag and putting stuff in that one, the old one was just piling over.
This morning I took a few bags of clothes to DI and got some coffee for the husband and I. I was happy and the girls were happy to see me. I walk into the kitchen to do something and discovered Shannon drew all over the counter panel (whatever the part of the counter that's eye level with her). She somehow got to a pencil and drew "spiders" all over it.
I'm tired, actually I'm exhausted, emotionally and physically.
We have an appointment tomorrow morning at The Children's Center for Shannon. She's getting a behavioral health evaluation or something along those lines. It's supposed to be a 2 hr long appointment. I REALLY hope to get something out of this. To be honest, some days I feel I need to be medicated just to keep up with her and her needs along with doing everything else I'm "supposed" to do..
Please no judgements or anything. I don't feel like I'm an unfit parent. I actually like to think of myself and pretty average. Right now I feel like I've just hit a bump or five in the road...