Back to the basics. Think back to the beginning and apply all the healing things you have learned.
I too have been diagnosed with PTSD and under extreme stress, it does rear it's ugly head. However, I have to remind myself I am in control of this and I have learned how to get through it before, and I will again.
Big hugs to you.
"I never knew how strong I was until I had to forgive someone who wasn't sorry, and accept an apology I never received