You could be copying him but... Growing up I've always talked to myself in my head, but it wasn't me. It was other characters I created. Some were male and some were female. Some were binary (before I even knew what that was!)... I used this as a coping mechanism as a child because I was very lonely growing up. So I only had me. Everyone including myself thought it was just a phase but I've carried it through even now at almost 30. I still go to myself for hard advice and to heal my own heart breaks and mental anguish. Only it's not me. It's primarily one of my male personas in my head. Does that make sense? I don't know if it's part of BPD or if it might be BPD and DID linking up but I won't even discuss it with a doctor I see as they will just laugh at me and slap a schizophrenic diagnosis on me. Last time I talked about it 8 years ago they told me those things don't exist *anymore* and I was just hearing voices.

From what I've read about that, BPD people do not have alters. We experience splits, which are different personalities, not necessarily identities. It very well could be that you're just mirroring him. BPD people don't have a comorbidity of DID but DID people could have a possibility of having BPD as well. It's a little weird to me, I've been researching this. Mainly because I'm curious, and because some of the patterns I'm seeing in my daily life seem like alters but I'm not sure if they are.

something thats helped me explain bpd to others (and myself) after i’ve split, is by giving it a name. i call mine “Mark” because it makes me laugh a little, and also makes me feel like i can overcome this, because in my head it’s just some stupid little guy called mark lol