It doesn't sound like DID to me, but I don't know for sure. I don't think you're being dramatic either. I do think since it's causing distress, talking to your therapist would be good if you could.

I don't know a lot about borderline, but seems like I heard someone say that it can have psychotic type features? I don't know if this is a psychotic feature though. I think the only way you can know for sure is by working with your therapist to figure things out.

Perhaps, if you are too scared to tell T about this, you could write it down and hand it to her. It might work to get information to her without causing disrupt.

Please let us know how things go. It sounds like it's a scary time for you right now. I hope you find peace soon.