If your son having adhd is a struggle for you, then therapy needs to be now, not later. Otherwise there's a chance you might start resenting him, and those feelings can be hard to get rid of after they get established.

Or, at least read some self help books specifically for parents of adhd children.

My wife figured out she was on the spectrum not too long ago, and me getting therapy and reading books for people in my situation really helped with being patient and understanding.

But, I made the mistake of waiting until things became an actual problem before doing it, so it's been a struggle for me to not struggle with it.