With the voices you describe and the behaviour you sound a lot like me. But I wouldn't say PTSD and DID go hand in hand. Typically PTSD is caused by a single event whereas DID is extreme repetitive trauma. But at the end of the day they are all just labels and what you experience will be the key. A therapist is definitely a good idea. Somebody who can help you with resolving what the trauma has left behind. Good luck.
-B