[muffinman26]

I think attempting to replace the easily digestible content with work is part of the problem.

You say you're opening a tab to HN when you're stuck or tired, but should be focusing on work. Your brain is stuck and tired because it needs a break. You can train it to do something other than switch to easily digestible content when that happens, like taking a walk or stretching, but you can't completely avoid a loss of productivity when you're stuck or tired. The brain isn't 100% effective all of the time.