I despise this feeling. It's the feeling of being beyond tired. All mothers have experienced this awful, dragging feeling. Most people have partied and gone to work and just suffered through the day. The difference with motherhood (I should say parenthood) is that there is no end. When I partied, felt hungover, had no sleep and went to work, I knew I could go home after work and sleep. Parenthood is so unpredictable, you never know if and when you will get a stretch of sleep to recuperate. It becomes depressing.
Simply dropping the ball (or the baby) is not an option. You have to get up, you have to make them dinner. You have to change them, bath them, shhhhhhh them and read to them. You then have to tidy up after them. At the moment I also have to tidy up after "guests" and figure out how to host a birthday party at our house when it was meant to be in the park. Damn unpredictable weather. Those kids won't be getting any party games, I tell you that!
I wonder when I will not feel tired. Ever? Never? Tiredness is one of, if not the most difficult aspect of parenting.