I'm sorry, Kiki. This happened for myself and for my daughter too. I learned recently that it's still happening on her visits with him and it made me very sad.
Ptsd, the little I understand of it, stems from trauma and the fear that another trauma may be rearing its ugly head at any time...that's some of my interpretation of it.
I've been told that one of the ways to begin healing is to face it.
During R that turned out to be false, I remember having this heightened sense of nerves, so that my skin felt like it was almost on fire or prickly, because I could never know if the next thing I said or did would have him out the door again. Eventually did and my stress/anxiety was that anticipation.
During that time, I would wake up harshly at night too and find my ears straining for sounds of him still in the house. My nightmare came true the night I felt wind come in the room from his leaving the door open to outside...he had gone outside to make his secret phone call plans for the final departure.
My experience with anxiety in general is that it's anticipation of a negative event coming.
I'm sorry that you're going through it...and yes, NIK has a good idea. Counselors can really help and be a safe place to put a voice to your fears.
A person is a person, no matter how small. -Dr. Suess
Perserverance and spirit have done wonders in all ages.