Perhaps my post will be helpful to OP.
When I was pg with DC1, as part of having my history taken at booking it was noted that I had previously suffered a sexual assault and had ongoing PTSD as a result. Unfortunately my hospital deals with a lot of asylum seekers from a particular region who have been raped, so all their staff are very sensitive to related issues. A note was placed on my file that internals should be kept to a minimum.
Fast forward to 33w when I am getting strong contractions and they need to assess if I am going into premature labour. They very sensitively and calmly explain that a VE is needed to assess if my waters have gone etc. I consent, and they proceed very carefully - lots of information, confirming consent frequently, I'm holding DH's hand, and so on.
Suddenly I'm terrified. I don't kick, because I can't move. Like a rabbit in the headlights, I can't do anything. Eventually I manage to squeeze DH's hand hard and say very quietly "I don't like it, please stop".
They stopped immediately and left the room ASAP. I then screamed and cried for a long time, clinging to DH like the world was ending.
They did absolutely everything right, and I still had that very visceral reaction. If I'd had less sensitive staff, or if DH hadn't been there, I don't know how traumatic that experience would have been. Internals are a very intimate and disempowering experience at the best of times.
The trauma comes from your experience of the situation, not necessarily the bare facts of the experience itself. So if you've never been scared enough to have that extreme instinctive "fight, flight or freeze" adrenaline rush, you couldn't know how paralysing it can be. And if you haven't been in that vulnerable physical position compounded by fear for the life/health/safety of your baby, you won't understand how irrational and nebulous your thoughts and feelings can be at that time.
I'm not permanently traumatised by that experience, or by two subsequent vaginal births, but I can easily see how I could have been. That bad experience did teach me that if I said "stop" they would do, and that gave me the confidence to relax in later VEs, which in turn made them less scary, and as a result less uncomfortable and quicker.