Don't expect that simply wanting to disconnect will be enough. Motivation without a system doesn't work. Walks and a change of scenery are good, but if your laptop is still in the apartment and you know the password, during a stressful moment you'll open your emails. The boundary needs to be not in your head, but in reality.
Try this: install an app on your phone that blocks your work email after a certain time - not just a reminder, but an actual technical block. For example, the app won't let you open emails after 6:30 PM, even if you want to. Or even simpler - turn off email notifications on all devices except your work computer and forget your email password on your phone. Sounds radical, but it works: when it's harder to override than to just not check, people don't check.
The second thing is not about rest on a schedule, but about getting back into the mindset before work. When you're finishing your office day, don't go straight home to your laptop. Even twenty minutes somewhere else - a café, the gym, just sitting on a bench - switches your head. And the main thing: for the first hour at home, do anything but work. Cooking, cleaning, a walk - your brain needs to switch to a different mode before it's ready to rest.