the problem is not your inability to switch off, but to switch on. This is rooted in the fact that too few people work in careers they enjoy. The only way to be truly successful is to follow your passions, find your mission, and learn how to embrace the work-life imbalance.
Overworking for something you like and think matters makes a lot of sense. Sometimes it may not even feel like work. Work becomes a burden when it competes against your interests. Happy work, happy people.
Fun work exists.