Relaxation isn't really a goal of meditation. When you do it you cultivate a kind of meta-cognition, an awareness of - and control over - the kind of invasive thinking that usually dominates our awareness.

As a fellow ADHD person I didn't get out the first few times I tried, but now find it quite helpful.

This. It's like you end up growing your own PAUSE button for the rest of your day and you can break your own fourth wall.

For me it just doesn't work but everyone is different, that's my point. And the relaxation is a prerequisite for having control.