Im a bit confused. here in America the term mental health is a cover all term to mean everything about mental health (it includes the good side of things and the bad like...mental disorders, treatment plans, how a person feels about their self, how a person feels about others, how a person interacts with their self and others....) its kind of like the term math covers everything from adding, subtracting, dividing, multiplication, geometry, ...

example my mental health right now is that I am happy with my life and those around me, I enjoy my work, I have bipolar disorder, PTSD, Multiple Sclerosis, my treatment plans include medication, various types of therapies to address my problem areas......

in order for any of us to really understand what you mean you need to tell us what about your mental health is in question, what part of your mental health do you feel might not be real....

just taking a guess because most if not all people when thinking about their mental health sometimes have trouble with believing whether their mental disorder is real or not that this is what you mean. if so theres an easy way to solve this problem. talk with your treatment providers they can tell you why and with what you are diagnosed with. if you still do not agree with them that these mental disorders exist in you, you can ask for diagnostic evaluations, here in america this is a series of tests that diagnose mental physical and learning disorders.