I have been diagnosed with adhd, but what if adhd is not real and rather i am just unintelligent...?

There are specific: Criteria that must be met in order to accurately make a diagnosis of add or adhd. There is also psychological testing that can to confirm if they are present.

It's real: It's very real. And it has nothing to do with iq. But some are arguing it is a learning "difference" and not a learning disorder. Indeed those with adhd may thrive without medication under the right learning environments for them, but unfortunately that requires great effort and the world is not always that kind.