For yourself the best approach respects your mental health and leaves you with the least baggage possible. Adding drama to the process prevents you from actually reaching your goal. Enjoying your future life regardless of which turns it takes.
Let’s talk about what separating can mean. It doesn’t have to take the years and years that most separations have to take. If you aren’t sure that this relationship has to end in divorce but you are sure it can’t go on like this separation and boundaries you set as part of it can be used to create a better future.