Unless you're Batman, working in a dark, dank cave of an office is not going to make you feel productive. While we can't all enjoy the amenities of a beautiful skyline view from our cushy corner office, taking a few steps to make your work environment pleasant will help reduce stress.
Putting up pictures of friends, family or adorable baby animals napping is one traditional approach to a happy work space. Instead of sticky notes with frantic deadline reminders, keep plants, flowers or even a calming candle on your desk. Even simple things like keeping your big to-do stack of papers handy but not directly in your line of sight can help you focus on the task at hand (instead of worrying about what you still need to get done). Remember that organization simply doesn't thrive under stressful conditions, so keep yourself motivated with breaks and rewards for diligence.
By making your space an engaging place to work, you'll relieve yourself of the panic that comes from dreading work.