I don't know if I have Dissociative Identity Disorder. can anyone help me?

Dissociative Identity Disorder (DID) is actually a very rare disorder. I've worked in in-patient mental health for five years and only worked with TWO patients with DID. What you describe sounds more like a form of PTSD than DID. If you were truly having dissociative episodes, you wouldn't remember them... you would black out... just as if you had too much to drink. Sometimes people --even close friends-- don't recognize an emerging personality for years, as it takes a while to develop. With your trauma background more chronic (long-term) than acute (short-term), PTSD is far more likely. PTSD often causes people to forget certain events or periods of time in their past that would be too painful to recall.