Hi- I have a nephew in which we saw many symptoms of add at home particularly surrounding executive functioning issues, impulsivity and some social issues with regard to the impulsivity ,but no problems were reported at school until he was about 15. He was eventually diagnosed with generalized anxiety as his primary condition with ADD being present but secondary. They treated both conditions but anxiety was most concerning.
My own son has been diagnosed with add and not anxiety. I am happy that he doesn’t appear to have the level of anxiety as my nephew , but I feel like there is still a missing piece to his puzzle which may encompass a chronic low level of anxiety around school and some social anxiety. It is very hard to untangle it all and certainly the last thing I want is another diagnosis or more medication for my son. But, I am researching and will be consulting his pediatrician about guanfacine. This is a medication that was used for blood pressure but many people are finding success with ADHD especially with the anxiousness that ADHD can create.
I feel for you. It can be all consuming when you know there is a missing piece. Maybe if you still feel strongly about the ADD you can consult a pediatrician/ psychiatrist about guanfacine since many have found success with anxiety/ anxiousness. Good luck.