If your imaginary friends do not actually...um, _become_ you and walk around and use your body, then it doesn’t count for a DID diagnosis, however there are similar diagnoses that cover conditions lower on the dissociative spectrum, such as DDNOS. A related condition is CPTSD. I am sure that your concern is legitimate and there is a name for what you are experiencing. If you read up on these and seek qualified advice, I’m also certain you’ll find out what it is and find some help. I remember feeling awful when I knew there was something not right with me but I had no idea what, or what to do. It was scary to not know.

Edit— Naturally I’m assuming that you do not know your diagnosis or that the diagnosis you’ve been given doesn’t capture your concerns. Please pardon me if I have assumed too much.