It's not toxic to say "all these distractions and interruptions stop me from doing what you pay me to do, here is what I need to do in order to perform my best work". It's toxic to tell that person that they're being toxic, which ADHD people tend to heavily internalize.
It's toxic to say your coworker asking for help is a distraction when all people are supposed to be there to collaborate and get things done together.
Imagine someone comes to your desk and says they need help with something and you say "Please go away, you're distracting me" or you simply ignore their presence. How would they feel?
I'm not saying OP is doing it at that level but I think you can see my point.
