The diagnosis dilemma

"Well Chris, I can confirm that you have ADHD - you've the type that combines both hyperactivity and attention deficit to a moderate degree. You're more attention deficit than hyperactive though"
This is not my first time through the psychiatry rodeo. Here in New Zealand you cannot get diagnosis of a mental health condition through a General Practitioner.
To get a diagnosis though, you have to be pretty confident that there is a problem, or be prepared to wait a hell of a long time. For me, I couldn't tell you what the problem was with any formal naming, but I could tell that I had a memory like a goldfish, distracted by absolutely everything and even the most miniscule of tasks could often paralyze me.
But it almost literally cost me a kidney to get seen relatively quickly, weeks instead of months waiting. Who knew the dollars per hour rate for a private psychiatrist is over $500/hr!
Getting a diagnosis is a multi-edged sword. The initial reaction is one of relief. Relief that you're not faking it, there actually is a problem, and now you have some actual evidence that you can throw back to the nay-sayers.
Quickly though, this feeling will change. In both cases (the first was for depression and PTSD, and now this) this happened. You go from a sense of relief to an anxious, desperation-like state. Or how I call it, the big 'oh fuck' moment.
This is when you realize that the diagnosis is actually not the end of the journey but the start of it. You analyze and question yourself and your being to the nth degree, and keep doing so until you lose sight of who you really are. When you cant beat yourself down any further, you then consider how your friends and family see you, and go through the process again. And then with work. And then in past relationships, and every other scenario that allows the black-dog to have its moment against you. Its truly terrifying.
Thankfully, the first diagnosis was taken relatively well by my co-workers, friends and family. The fact I had something to 'blame' as a cause of it (my time as a soldier) was seen as almost a reason to believe that it was OK to be like this given the circumstances, and this quickly enabled me to recognize that I wasn't the problem, but rather, I was being affected by a problem.
This time around, not so much. 45 years to figure out coping mechanisms, strategies to mask and manage my 'uniqueness', why didn't I know sooner? Why hadn't I done something about it? Why do I have to make my problem, everyone else's problem?
Its been about 4 weeks into having a diagnosis and I've already beaten myself up, re-mulling things from my past to figure if there was a better way of handling the moment, the individual or myself. Then learning that ADHD has a strong likelihood of being hereditary the concerns of self quickly turn towards my children. Are they ADHD too?
Suddenly I'm no longer a father who unequivocally loves my kids irrespective of whether they're being good or bad. Now I'm constantly watching them for any sign of anything that could look like ADHD. I'm asking their teachers. I'm comparing them to their friends. I'm asking their friends parents in a sly way to see if they've seen anything that could be ADHD. I feel like an asshole for doing it, but defend my actions with the belief that if there is a problem we can get it addressed now before it affects their life like it has mine.
Then there is the stigma. Being sidelined at work due to my inability to create a PowerPoint slide deck with any meaning in any reasonable time. Feeling excluded from the conversations, missing out on the details. Now more than ever all I want is to feel accepted and a valued part of the team. Instead, I feel li