Can BPD ever kind of look like DID, for example if you suddenly "split" on something could it mimic DID? I'm on the waitlist for a new therapist at the moment but I just wanted some opinions on this so can know what to make sure I bring up when I do go to my appointment.

For a very long time, I've thought of my brain as my "logical brain" and "emotional brain". When my emotional brain is freaking out, for example I'm feeling terrible thinking my FP is abandoning me, my logical brain will like "step in" and say kind things in my mind to the emotional brain or argue with it that my FP is not going to leave me for example.

When I told my therapist about this, she kind of made a "look" at me and told me I needed to integrate my brain into one brain. I also told her that when I'm remembering my trauma or having a PTSD flashback that I feel like I've shifted back into the person I was back then.

Sometimes there is a more distinct shift between the two parts. For example, this evening, I was feeling pretty suicidal and depressed because I felt like my FP was abandoning me, then my brain concluded it did not actually want to die even though I still really felt like dying, and all of a sudden I felt a distinct shift as my body language, thought process, and posture changed as I kind of shut off emotionally and shifted into a distinctly calm, logical, and nurturing "persona" similar to how the better parts of my hypomania feel sometimes, with the clarity of thinking, logic, intelligence, a bit of narcissism, nurturing kindness towards myself, and suave pursuit of various ideas I feel suddenly confident in pursuing.

That shift has happened before in times when I'm really stressed or depressed, which I have been lately. At work a lot I've had to shut off emotionally and just kind of go empty and numb and logical in order to cope with being there.

My brain always had the "logical" and "emotional" parts, ever since I was a teenager and started experiecing depression, but after my trauma that I have PTSD from (which happened nearly 6 years ago), the shift became a lot more distinct. I had to "turn off" emotionally, dissociate, and become that distinctly calm, logical persona during the duration of and after my trauma. Any person OTHER than that couldn't have survived what I went through, so I had to shut off emotionally and shift into that. When I shift into it now, it feels the same way as it did back then, but to be fair a lot of things have triggered my PTSD lately. But neither of these parts of my brain have different names, hobbies, memories, etc - it's just that one is emotional and one is logical, so they act accordingly. 

And while the emotions themselves are distressing, and it feels weird to shut down emotionally and feel empty, both parts of me existing and changing as they do aren't distressing. Considering the emotional part of me is likely more "me" and the logical part steps in sometimes to help, I actually appreciate the existence of the logical part of kind of "save" the emotional part when I'm feeling really crappy or suicidal or whatever.

In your opinion, does this sound like the shifting between different alters in DID or does it sound more like it's just me splitting on myself or me having an intense mood swing from depression to hypomania?