Happy to help! Heaven knows that I've gotten sooooooo much more from this forum than I've given back.
Hoagies is a wonderful website for GT families. I recommend exploring it when you have a chance, if you haven't already.
To answer your question, yes, I think pretty much everyone here knows how you're feeling. I know I was often the quiet one at playgroup because my child was at a very different place developmentally than the other kids. And I think a lot of the kids in the group were at least MG, which explains why I wasn't aware of just how GT DS7 was back then. But he was still visibly different.
So please feel free to "brag" here about your kids to your heart's content. Personally, I *LOVE* reading good stuff about kids--all kids, GT or not! It makes me happy to celebrate their amazingnesses.
(Or if you need to, feel free to complain about how hard it is--that's something else that people don't really seem to get about these HG+ kids out IRL...)
And just to make you feel a bit better, I hope, I went through the same feeling about starting too late. I think that's part of coming to grips with what we call "GT denial." I knew enough about GTness from my own childhood (my mom started a GT support group back in the late '70s, so books and magazines about GTness were all over our house when I was a kid) to know that DS7 was GT. But I figured he was "just" MG and that he would have an easy time at school.
My awakening came after I saw how high his achievement test scores were on his teacher-ID'd GT testing in K (just shy of 6yo). I was shocked. We had books in the house for as much as 3rd graders--4 years above grade level should be enough, right?--so I had felt like I was doing pretty well. But there was nothing for DS7 above that. Then I saw that he was testing as reading like a middle schooler at not-yet-6yo. Yikes! The guilt I felt for not giving him what he needed was awful!
On the bright side, you feel it and you get over it. Those feelings are part of the natural process of dealing with an HG+ child, I think, but you can't change the past. Figuring it out at age 6 is a lot better than it could have been, after all, and it's plenty early enough to make a difference.
My advice, FWIW? Allow yourself to feel guilty for your shortcomings and to mourn the easy, painless school career you dreamed of for your child...for a while. Every child is different and all the kids discussed on this forum have taken different educational paths, but I don't think any of the parents here would say it was easy and painless for them. It's one of the big things we all have in common. (Of course it was easier for some than for others. Some lucked into a cooperative school right away. But even then, there are constant insecurities and dilemmas.)
But feel those feelings and then forgive yourself as fast as you can. The next stage in the process is taking action to get your child what he needs, and it's a lot harder to do that if you're crippling yourself with guilt. (Trust me! I've been there!) You're doing what you need to do, so let go of the regret and the self-recrimination. You're a good parent and you're doing what you need to do now. That's all that matters.
Besides, you obviously weren't doing *that* bad of a job if your child knows what he knows, right?
Welcome to the journey!
