How did you know it was adhd and not just depression/anxiety

When I am supposed to be working my mind is constantly thinking about what I want to be doing and not focused on what's in front of me. E.g. fantasizing about listening to music, scrolling Reddit, watching YouTube, meeting up with friends, getting another cup of coffee.

I can focus eventually when I force my brain to, and some coffee. I do not have "a million tabs open" in my head. I do not procrastinate to the extreme extent. My doctor does not think I have inattentive- adhd, I am still not sure.

So my question for everyone here is, how did you realize you for sure (before professional diagnosis) you had ADHD and not just depression/anxiety?