I understand the PTSD; it happened to a good friend of mine while on holiday. We'd rented a jeep for the day; we swapped drivers after lunch, when, suddenly... he was freaking out at the wheel! We stopped, talked about it and the memories flooded back of his near-fatal and fairly recent motorbike accident. We decided to break through the feelings and regain his confidence; it was off-season and not many other cars on the road. It seemed to have worked.
On the second day, we went off-road climbing up mountains - he was determined to drive. It was my turn to be shit scared!
We were fine!
Oh my. Yes, you never know when the images will start replaying in your head- out of nowhere.
SO glad you were there to help talk him through it. That is important. You are amazing and just what was needed <3