Stand up. Stretch. Take a ten-minute walk. Loosen up those neck and shoulder muscles.
When it’s work time, do the work. Then take a break. Then get back to work.
At some point, take a longer break. Break for the day or for several hours. Build the other parts of your life. Don’t carry work around with you. Focus on play time, family time, rest time. Work isn’t life. Work is part of life.