Welcome to the network, Alison. Thanks for sharing these thoughts and experiences, I’m happy you survived and are here to tell your story.
There is still more research to be done before we can speak definitively on the matter, but there have been a handful of self-reports from individuals sharing they acquired aphantasia in response to a traumatic experience or as a defense mechanism to PTSD. I’ve also seen a few people reporting they lost it gradually and suspected it was a result of taking anti-depressants. And then there are the better studied cases of aphantasia acquired after forming a brain lesion from a stroke, like patient MX.
But of now, the data suggests an overwhelming majority of the community is made up of congential (since birth) aphantasics, but there are still many undiagnosed aphantasics (at 3-5% occurrence there are an estimated 300 million aphantasics). One thing I believe it’s safe to presume that their are various types of aphantasia, likely stemming from various underlying mechanisms.
As more studies come out, I will try to share links to studies relevant to trauma here for you!