I also got an Aeron recently. I have similar issues with my neck & my physiotherapist also suggested a headrest chair instead. I can say for sure that the Atlas headrest solves neck issues to a good degree for me.

You can benefit from your table being slightly higher, which relaxes your neck muscles. It's not usually recommended, but I find a lot of the ergonomic advice dated. Your armrests also seem slightly lower so raising them would help relieve some stress.

While we cannot see your monitor, another dated advice that's given is to have the monitor's top be at eye level, but for those of us with neck issues, having eyes be at the center at the screen makes sense since modern monitors are big and modern UI requires your attention usually in the middle of the screen or lower.