TL;DR: New therapist is making me doubt my trauma from neglect because my intrusion symptoms aren't picture book PTSD (no visual flashbacks, no specific individual events my trauma links/refers back to) and says she'd be wary for now to call my experiences (complex) PTSD.

(possible TW for trauma from child neglect)

EDIT: I'm Europe based, so DSM-related comments I can't really utilise/relate to well. We use the ICD-11 here and complex PTSD is a recognised condition separate from PTSD. Do feel free though to still add your responses for others to read!! :)

I started seeing a new ("trauma-informed"/"high-intensity") therapist recently (we had our second session yesterday) and though she's incredibly kind and empathetic, it seems to me that she's really keen on diagnosing/treating me with only PTSD in mind, despite acknowledging CPTSD existing and acknowledging it being much tougher to treat. I do understand she's being careful, not wanting to offer a wrong diagnosis/treatment and possibly making things worse that way, but it certainly didn't help when she said she's not too sure yet whether what I've been describing to her can actually be classified as CPTSD.

As for many of us, my flashbacks are mostly emotional flashbacks; suddenly getting triggered by someone's behavior that reminds me of my mother's behaviors and immediately feeling intense panic, overwhelm, and self-hatred (lots of shame and guilt). My mind scrambles to try and figure out how to best act in order to appease the other person, even if there is absolutely no need for it. Being triggered genuinely feels like the world around me is crumbling and nothing will ever be okay again, everything around me turning dark and things appearing utterly pointless because of how my mind is telling me I completely effed up and will be abandoned all over again for not having been better.
My new therapist says flashbacks have to have images or sensations linked to them. That me startling and panicking when I hear my flatmate's key in the door when they come home is not a trauma response.

It basically eventually all boiled down to her saying she can't tell yet whether I'm really traumatised or whether I've merely had a few negative experiences that led to negative core beliefs, and that it's those beliefs/the resulting anxiety and avoidance that I act on now.
She further based this on the fact that I don't have any specific core traumatic memories. Obviously, the emotional neglect I experienced from my mother was constant; her behaviors never changed and my reactions to them were the same over and over again with each time I was hurt or disappointed.
I told my therapist about my nightmares, but she said they have to be about a specific event in order to be considered related to trauma, and that my nightmares always being about abandonment and the pure terror of perpetual loneliness I feel in them is not relevant to that and merely indicates I had a lonely childhood, but is not necessarily a sign of trauma.

I guess I'm mostly just looking for validation here right now... It'd be nice if you could leave your thoughts/experiences to ease my anxieties surrounding this because I genuinely feel so invalidated and, obviously, the whole thing pushed me into a flashback yesterday...
I'm also honestly just not quite sure how to explain any of this to my therapist. She gave me the homework of logging intrusion symptoms and nightmares until our next session, but how am I even supposed to do that if she doesn't see my intrusion symptoms as trauma-related and considers them overthinking due to anxiety?