I think mummies tend to be more prone to this. Especially those that stay-at-home. We tend to lose our sense of identity and self worth. Then the bad moods strike... and we slide down into confusion and meyham. Been there, done that. Even sought professional counselling at one stage. Solution? well, different things work for different people.
For me, getting involved with a volunteer group like BMSG gave me an outlet to talk and help other moms. That added purpose and color to my life. It also reminded me that compared to others, what I'm facing may not be so bad.
Being active on parenting forum like this one is also fun... I get to vent when I need to, ask questions, and offer a shoulder to cry on. Either way, posts sometimes manage to cheer me up when nothing else seems possible.
I also took up a personal development course that I'm thoroughly enjoying. Its online and I do it at my own time whenever I can. I'm learning to set personal goals and fulfill them. I'm also learning more about improving my relationships with both my hubby and my children.
hope this helps.