With your couselor giving context for the grading and the rigor of the school, you should be fine. This, btw, is known as a school profile. You can find these on the websites for most private high schools in the US. If your counselor isn’t sure what to write, those could be a good template. This will likely be important if your school has little history with US colleges.
Also, beware of thinking that with that understanding, AOs will view you as the equivalent of a top student from a top high school in the US and admit you just like that. Believe it or not, there are a few high schools in the States that are quite selective and competitive, and plenty of top half unhooked kids end up with far less stellar college options than they’d expected. As you no doubt know, highly selective schools get piles of applications from piles of excellent students (often from excellent high schools), so there are no guarantee for unhooked applicants.
You sound like you have an interesting background and are a capable student so make sure your essays show how that, and the person you are (whether because of it or not) will make a contribution to a college community. Do your resarch and make sure your list includes some likely schools where you would be happy. While the odds are that some of your matches, and even reaches, may be excited about you, there is always a distinct chance that something doesn’t quite come through as you’d hoped in the 5 minutes your app gets with a reader , so make sure you will have a few sure things in the end.
My guess is folks here could help with your list if you are still working it out. Good luck to you!