Is OCD considered a mental illness?

Yes, it's a form of mental disorder

Yes, it is a form of mental illness. See the DSM-5 on the subject.

Psychiatrists are certainly "real doctors". They receive the same medical school training that other doctors receive and are MDs. They are trained to diagnose and treat mental illness and are licensed to prescribe like other physicians.

The Anon who posted that lengthy ranting diatribe about psychiatrists appears to be suffering from a mental illness himself. Pay no attention to that sort of thing. We see a lot of it around here.

emotional … not  mental.          

Yes. 

"Mental illness, also called mental health disorders, refers to a wide range of mental health conditions — disorders that affect your mood, thinking and behavior. Examples of mental illness include depression, anxiety disorders, schizophrenia, eating disorders and addictive behaviors."

- the Mayo Clinic

If you don't like that label, you can call it maladaptive behavior. 

Yes, that's a psychiatric disorder. 

no..........................