Hi, andrewc, welcome to OOTS

***TRIGGERS throughout the following***
You asked if others have memories of very, very early core trauma? Sadly, I have a major one that, given that I've carried it my whole life and floats into mind daily, will probably never cease to haunt me. Yes, of course I'm seeking to release its grip any way I can, but it's been a long, hard slog to find any daylight from this.
I'm not up for much detail at the moment (or ever, at risk of being violently sick), but the basics are stuff that happened in a crib; my memory is too clear on that and has never deviated or been somehow confused with anything else. While some memories can be vague, that one has always been crystal clear. So there's my first inkling.
In the years that followed infancy, even way beyond the crib molestations, I recall the m doing unsavory acts (and yes, they did seem 'wrong' even before my mind had a clear notion of right/wrong). Many times these happened in or en route to bathrooms. As I grew older, she'd just burst in (no inner door lock). This often caused constipation as I feared going to that grim place. Fine with her--she loved using enemas or suppositories; all for my good, of course.
This continued until age 9 when in retrospect it seems the f found or figured some of this out, disapproved, threatened to leave, and the bathroom visits ceased. I actually don't care why anymore (I was seeing a child psych at the time at the f's behest)--all I know is that the abuse just migrated to other forms--not as directly physical but fully as devastating. But the worst part was--somehow the monstrous actions on her part were blamed on me!!!

My fault? Talk about adding insult to injury...blame the victim.
Regarding the crib memory, for years I'd hoped that had been and was still somehow an illusion, an aberration of my mind. Nonetheless the memory remained certain and clear. I had no doubts, but still in some desperate hope for a 'false memory' I allowed a very reputable tribal shaman, who knew nothing about me, to undertake a psychic retrieval process about 10 years ago. I was, and remain, highly skeptical of psychic methods. But in this case I was insatiably curious to confirm as best as I could my lifelong suspicions--it didn't involve money or other gratuity, I wanted another angle, the shaman seemed very trustworthy, and so I consented.
Basically, he entered a trance state knowing nothing of my past (we had only met about 5 minutes before he began). He didn't ask, and I didn't tell, any of my story--zilch about anything. So his 'journey' was undertaken in general terms, trusting his own inner process. When he reported back to me afterwards (I was there the whole time--several hours), he indicated that he'd noticed a sordid string of incidents with an adult woman (he didn't identify her as the m) all the way back to infancy and, at least by his determination, this was real. His detailed description of the surroundings matched my own too-vivid memory as well. Science can scoff at this, but I was sure after that point that my memory had substance. Of course I already knew the 9 hellish years that followed, no psychic/shaman needed; but those also were witnessed in the process.
In a way I felt relief that my memory wasn't off base, but it also was devastating in so many ways. I had no reason to doubt his veracity...he didn't set out to find harmful info, but reported honestly on what he'd found. Plus there were an abundance of other things he noted, all 100% accurate according to my memories.
So that's my experience. Not pretty. I'm ashamed to have had a role, even an innocent part, of the m's apparent glee in what she did. And I have to stop; this already took me longer than I thought it would.
I wish you well in your recovery process, andrewc.