I didn't get PND but I do understand some of the panic you feel (can't believe you had a second child - I've not gone there yet). When my LO has a bad dream I feel literally sick with the thought that we will both be up all night. BUT it is amazing how rarely we have a terrible night, and it is usually caused by me trying to get back to sleep too quickly without reassuring her enough, or not wanting to submit to the reality that some dreams are bad enough that she needs to share our bed for the night. The reality is she isn't a baby and now thank goodness she can explain what is wrong and understand my reassurance. I agree with PP that maybe you need some help learning how to let go of the past reality and embracing the new one, because you wasted 5hrs (when you could have been sleeping) worrying that you weren't going to get any sleep, which ended up being worse than what she would have brought you!