Valdeeves/Ewan - sorry you're feeling a bit gloomy. Here is my prescription for you both:
Wrap up warm in whatever clothes are close to hand. Sod what they look like.
Forget washing (clean teeth only!) and just go out. Get in the car and go to a park you don't normally go to, or walk if you can.
Feed the ducks.
Run around.
Go to the farm and feed the animals/stroke the rabbits.
Have lunch in a cafe.
AND LEAVE THE BASTARDING HOUSEWORK TO GET ON WITH ITSELF FOR THE REST OF THE WEEKEND!
No point putting it all away as it will be just as bad by the next day.
Then when you get home, jump in a bath all of you together with lots of bubble bath and sod the wet floor. It's water, it will soon dry.
Out of bath, in your PJs, snuggle on the sofa and watch a DVD.
Order a takeaway
Open a bottle of something lovely.
Or - if you've got someone who is at home this evening to look after the DC, call a friend and suggest an impromptu night out. And GO OUT - don't stay in, even if it's at their house.
Forget that you are a mum for a while.