They've said women with this condition often develop post-traumatic stress disorder, but it doesn't make sense to me to call it PTSD, because you're not post-trauma. You're thinking seriously about *going back in*, and the potential crisis isn't over yet.
One thing that can help is to consider the risk you run when you drive to the grocery store. It's probably quite a lot higher than the risk you run getting pregnant again with good care, but you're used to it.
The risk to the fetus is however fairly high for some women depending upon their underlying conditions, because the way they protect *you* is to deliver, regardless of gestational age. But in most subsequent pregnancies preeclampsia appears later, and more mildly. So another thing that can be very helpful is to talk to a MFM about how a subsequent pregnancy would be managed. Since you developed PE at 27 weeks last time, have they checked for any underlying conditions that might be predisposing your pregnancies to become preeclamptic, and could those conditions be better managed? Would they give you steroids at symptom onset to mature fetal lungs? At what point would you be admitted for close observation and quick delivery if necessary?
I hope this helps.