I'm not cut out for this

I feel so blah.
I cannot get motivated.
My son is annoyingly naughty. He keeps getting into the fridge and getting things out, he just gets into everything, truth be told, he is driving me fucking crazy. He keeps climbing out of his cot when he is damn tired and needs a sleep. He keeps biting his sister, hitting his sister and annoying her.
My house is trashed, it's almost all back together, but the task of cleaning it up and putting it back into order is such a huge task I'm overwhelmed and can't do it.
Both kids have been sick for the past 3 days. I'm running on little sleep, so I'm tired, and grumpy, and angry, and unmotivated and generally feeling so very blah.
I haven't gotten dressed for 3 days, I just shower and put my jammies back on.
It's raining and windy and miserable outside.
The cartoons finish soon, and the prospect of having to entertain Leeara is not a good one.
Yes I am a terrible Mum. I'm not cut out for this life.