If there an “entity” that has overtaken your mind, it might be something other than schizophrenia such as dissociative identity disorder (DID). Perhaps the idea of an “entity” is suggestive of a delusion. You also mentioned covering your phone’s camera because you fear that someone is watching you. That could be indicative of paranoia, a common symptom of schizophrenia and related psychotic disorders.
Of course, diagnosing over the Internet is impossible. Much more information is necessary to determine if you have a disorder. I would advise you to have an in-person evaluation by a mental health professional. If you are experiencing symptoms, you should always consult a professional. They would be in the best position to determine what is wrong and most importantly, to offer treatment.
All of the symptoms you have described are treatable but they first must be brought to the attention of a mental health professional. Ask your parents to assist you in finding a professional in your community. Please write again if you have additional questions. Good luck.
Dr. Kristina Randle