I love RVing and GENERALLY find it relaxing...
That being said, there are some things that CAN be stressful. Driving a big vehicle, backing into a parking place, "fighting" to get things level, making sure you have enough water, battery, gray tank capacity.
I know little of PTSD, but I think I can say the issue isn't really THE stress but HOW YOU HANDLE the stress. I tend to enjoy backing into parking spots, but one recent dark night with a narrow site and dealing with stuff on the blind side of the trailer...it made for a challenge...another time was a cold night with a weak battery...and there have been some nights with storms about, where we wisely monitored the weather.
I'm worried that you don't know what your triggers are...again, it's generally relaxing, but there are some stresses. Most of us enjoy those stresses, but also have been known to crack open a beer at the end of a trip and after hooking everything up...