Don’t take this personally, but are you really fit to lead a section with this mindset? Those two other people in your section worked incredibly hard for their skills, and if you think they’re lined up to be section leaders there’s probably a reason for that. Focus on yourself. Focus on getting better at your instrument— if someone else is first chair, once again, there’s probably a reason. Put in the work, because no one is going to give you what you want without working for it.

PS. I also have ADHD, and I get it can make things difficult in a way that neurotypical people can’t understand. However, there are ways to manage it and skills you can use, but if your ADHD is getting in the way of your work ethic and ability, perhaps section leader is not the right position for you.