Set a time (for ex. 9:00 pm - 10:00 pm) as wind down mode and whenever you open the app it first shows „wind down time“ and maybe the app closes itself after 5min of usage

Set a time (for ex. 10:00 pm - 7:00 am) as sleeping time. The app won’t open directly. You have to take take 15 deep breaths to open the app. A broadening and closing circle helps to breath.