Some brutally honest posting here.
Since dd1 was born 4 years ago, I have struggled with recurring periods of restlessness, when I find it very difficult to reconcile my responsibilities as a mother with the loss of my old self - the one who didn't have to constantly put the needs of others first.
But it's an ongoing process, isn't it, acquiring the mental, physical, and spiritual resources needed to do this "job" properly. It's such a major process changing the priorities in your life for good, and I think that it is just unrealistic to expect to be able to do this over a relatively short period of time. I've come to the conclusion that it takes years to re-evaluate and adjust the entire focus of your life.
I also think you need to be actively wanting to make the change before it happens. I reckon it has taken the best part of 4 years for this to occur with me. I'm sure for others it can take much less time, much more - and perhaps, sometimes, never.
Would I have had children if I'd known all this beforehand? Yes, I would, although I don't find it comes easily. I am, slowly, learning to adapt. And I find what HZL said very true, especially the bit about imagining the more exciting and glamorous life that you would have had if you had remained childless. Making the most of what we have - and it is so much - is so much better than regretting what we have been and lost. I have found you can't live your life at peace with yourself if you're trying to get back to somewhere you just can't return to.