Thank you for writing. I’m sure this is very confusing and worrisome. You’ve described a complicated set of symptoms, much too complicated for me to respond to responsibly on the basis of a letter alone. The diagnosis might be DID but, depending on more details, there are several other possibilities as well.
I therefore strongly urge you to make an appointment with a mental health provider who can take the time to hear your entire story and who can ask questions that can help with accurate diagnosis. Once the two of you have determined what is wrong, he or she will be able to offer you some treatment recommendations.
I do think you need treatment. Not only are you having serious symptoms, but those symptoms are interfering with the important social and cognitive development that should be going on during your teen years.
Please ask your doctor or school counselor for recommendations of local therapists who specialize in adolescence. You deserve the help.
I wish you well.