Newly diagnosed, need to get some stuff off my chest

Hello! I have recently been diagnosed with DID, and I am very confused and self-doubting about a lot of things. I hope this is allowed, I just wanted to write down some of what has been happening to me and some questions and see if other people find that it's similar to their experience of DID. Any response is appreciated. I don't think there are any specific triggers here, but I am describing my experience in depth so it might be a bit upsetting in places. I also want to be clear that I am not saying that DID doesn't exist, just that I am not sure whether I have it. Apologies that this is such a long post.

So I'm a 25 y.o woman. I come from a very unstable and abusive background, like most people here I'm sure. When I was about 10, I got into a piece of fiction that really meant a lot to me (will be important later). A couple of years later, I started to often picture myself as a man and I even thought that I might be trans. For the first time when I was 12-13, one of my friends said I "had two different sides to me", a thing that people have often said to me over the years, but I thought they were referring to when I was depressed vs not. As the years went on, I often found that when I was stressed, I could step outside of myself and "see myself" as if I were standing next to myself. When I was about 20, something happened - I remember being so badly distressed that my mind kind of snapped under the strain and I just laughed and felt hysterically happy for a few hours, and all my aches and pains were gone and I felt amazing, and was kind of acting like I was drunk or high. I was diagnosed with BPD, but there was something I never told anyone, because it didn't seem worth telling, which was that I had a very intimate relationship with an imaginary man.

I literally just thought I had an imaginary friend, so I wasn't in a hurry to admit that to anyone. He was also able to kind of shapeshift into anything I needed him to be - mostly a kind of protective brotherly type figure, elements of my dad, of musicians I like, and of a character from this work of fiction (he has the same name and more or less considers himself to actually be that person). Of course I thought I was just a bad fantasist and was kind of embarrassed about it, so I didn't tell anyone for many years. However, over the past couple of years, I found that I was completely unable to switch off the fantasy life that he had in my head. Literally all the time that I'm awake, he's in my head living his own life, having conversations with people, making tea, doing things anyone does. I cannot turn it off, and it's huge and all encompassing, to the degree that I can't even focus on my own life a lot of the time.

This became worse and worse until I could actually see him and hear his voice. For days or possibly months I was unable to get away from him. It really scared me, I thought I was possessed or in a psychosis.

When I went into therapy, the same day that my therapist told me I had D.I.D (she did a screening, and she is qualified to diagnose D.I.D), my alter spoke to her. This had never happened ever before and I was scared stiff. The experience for me was like being drunk: I could hear myself speaking and feel myself moving, but it was like my consciousness was very small and unable to interfere in what I was doing. After I spoke the therapist, I remained in this state for a long time. In some ways I felt like myself, in some ways I was thinking about myself in the third person and thinking and doing things that were completely unlike me. My anxiety and physical pains were gone, and everything in my brain felt different. I wrote myself a letter (or should I say my alter wrote me a letter?).

Since then, I have been able to do some cool stuff like feel as if my right hand belongs to me, but my left hand belongs to someone else, and stuff like that. I have also become more convinced that I am male in addition to being female. However, I still feel strange and like I might just be wishful-thinking this whole thing. My biggest questions are these:

• What my alter looks like changes. Is this weird, or possibly an indication that it isn't true DID? It's like, who he is stays the same, but he is played by different actors. For example if I was listening to a lot of David Bowie, I would think my alter looked more like David Bowie, or if I was watching Dr Who I might think he looked more like Matt Smith. For me, this is one of the biggest things that makes me doubt that I have DID, I feel like I just have an overactive imagination.

• While I have heard voices and been followed around in my life by an imaginary person before, that person was not my present alter (if indeed he is a real alter). So again, I don't know whether I just have a really strong imagination and can create the person I need at the time.

• I am kind of terrified of losing this person, whether he's an alter or not. I would be really lonely to think "Oh no, he's just a book character, he was never here and I'm alone again."

So... is any of this how you feel? Is any of it a sure sign that I don't have DID?

Thank you to anyone who read to the end, I hope you have a good day <3