What also helps is just shutting the computer off and going for a walk, generally the moment you step away you'll figure it out!
By the time you're done describing the problem and its symptoms, you'll have a solution.
I can also recommend going for a walk. I usually return from long motorcycle trips with the best ideas. Tea on the balcony is also effective.
Underrated. Diffused mode of brain.
1) Find an employer who doesn't pay by the hour (but e.g. per day or task/goal)
2) Find an employer who isn't strict on the hours.
3) Self employment.
4) Find or convince an employer who accepts this.
None are ideal, except for #4, but its the long breath.
And I am thoroughly convinced it works. Same with workout, mindfulness. Such behavior should be rewarded. My employer supports workout in the sense I get 1 hour per week paid leave for working out.