There is a perception that successful people work 24 hours a day, but this isn't necessarily true. The real reason people are successful is that they know when it's time to work and when it's time to play.
You must learn to take some time out of the day for yourself every single day. If you don't make time for yourself, it can have a serious toll on your physical and mental health. You'll drive yourself to distraction thinking about all the things that you're not doing or that you should be doing or that you didn't do correctly. Learn to turn your "work brain" off, and enjoy your personal time. You'll emerge more rested and recharged, ready for the next challenge.