precipitous labor?

I don't know if this forum is where I belong. I don't like the implication of the name of it. But I'm not sure where else to go, so here I am. I hope to hear of other stories like mine.

I have two children. My older daughter is 4, my younger was born last October. My first labor/delivery was longish (18 hours) and constant hard work. I was euphoric afterward--the opposite of PPD, if there is such a thing. My second labor was fast, intense, out of control.

I read a story today written by a Mama who had a similar birth, which she felt left her empty. She felt something had gone out of her with the intensity, and it took her four years to fill up again. She came out the other side of her labor a different person.

I resonated with her story in an increadibly strong way. I don't feel depressed. I feel different. Empty, lonely, yes, maybe. But more than that I just feel different. I'm not sure where or when I'm going to land (or be filled up, in the other Mama's words).

But she was a young, single Mama. Which in general doesn't have it's benefits, but perhaps in this case it does. She was only accountable to her daughter. I have two daughters to be accountable to, plus a wonderful, devoted partner. I have a house on some land, I have a dog. I'm most of the way through a Ph.D. program. How can I be empty? How can I not be devoted to these, my loved ones? Where do I find time and space to find out who I am now? And how do I tell my loved ones that I've changed, but I'm not sure how?