I did this to myself, for very good reasons, so I am not complaining nor do I regret my decision to start trying for the second child so soon after the first one was born. On the other hand, may I heartily recommend that if you are thinking of having more than one child that you yourself choose a much more sane spacing, unless of course you have equally compelling reasons why you can not.
Caring for a toddler and an infant is an interesting balancing act. Sometimes the infant sleeps when the toddler needs attention and the toddler occupies herself while the infant needs breastfeeding and when that happens all is right in my world. Sadly, that is not always the case. Mornings are the worst. Mornings are when I find myself trying to manage two babies who often both want food at the same time, and one of those babies is mobile and one requires some care to carry on account of being brand new. In general I love parenting, but I don't love it when it seems like I'm having to choose every particular moment which child gets to cry right now while I attend the needs of the other. Duncan is still a small enough baby that he will lose a latch if jostled while breastfeeding, which makes doing much of anything while feeding him difficult. I've tried reading to Margaret while feeding him, but... well, let's just say that reading to Margaret is a more physically interactive affair than you might guess.
It will get better. Having my mother up here for the first week was a real sanity saver. Alas, she can not stay forever. I expect things will be better by the time I return to work, at which point they will likely get worse again as we will have a whole new routine to get used to.
In related news, I was right about the minivan. With two wee children power sliding doors are more of a necessity than a luxury.