How do you deal with the fact that you won't be having anymore kids?

How do you deal with the crushing realization that you won’t have anymore babies? I just had my second, and last, four months ago. Between my fiancé and I we now have 4 children, and we both agreed that this will be our last. I also have had 2 miscarriages. I’m struggling with PPD, as well as a lot of health issues and I just CRY when I think about not having anymore. My pregnancies were all so awful, but yet I want to go through it again? I hold my baby boy and long for time to slow down. I’ll never have a newborn again