Isn't there a similar study where playing Tetris helped people recover faster?
It was used to keep people awake for a long time immediately after a traumatic event. The Tetris was less important than the lack of sleep.
If you don't sleep and play Tetris for a couple days you scramble the process of turning short term memories into long term, making them less impactful.
I'm curious because my therapist said I probably have CPTSD (not as severe as your ex had it, though; to the point it doesn't even sound like CPTSD to me).
The 'apparent severity' of PTSD has more to do with the pattern you fall into.
"In short, there is no convincing evidence that playing Tetris actually helps people. The studies have methodological problems, tiny sample sizes, and have failed to replicate. Some found a reduction in “intrusive memories,” but no improvement in outcomes of PTSD or distress."
https://www.madinamerica.com/2021/10/tetris-trauma-viral-twi...