Borderline, or multiple personality?

My therapist thinks that I may have DID (multiple personality) but I am kind of leaning more towards borderline. I seem to fit some criteria of both of them, but am not sure. I go into what I call episodes where I at the flip of a coin, get extremely suicidal, cut my self, pace around, and it ususally starts from me taking something the wrong way entirely. I drive differently, and do really odd things. Then other times (when I meet new people) I am extremely outgoing, and speak in a southern accent. I never notice until someone mentions it. I am not sure that I completely remember everything that happens during these times, but I get the main gist. I also cannot seem to establish a relationship due to mistrust and fear that they dont like me, and me taking certain things the wrong way, etc. Recently this girl I like and I went to a bar, and when I went to the bathroom she forgot I was there and left, I gto so upset I almost hung myself over it. Is it possible to have more than one personality disorder? Anyone with either of these disorders, any advice?? I am just afraid because if it is alters, one of them is very suicidal...