Stressful moments often require that we take a step back and just breathe. Deep breathing exercises that you can take to work can help reduce stress during those times!
Sometimes you need to walk away from your desk, emails and phone and get some air. Give yourself regular breaks throughout the day to help decompress and clear your head.
One of the best ways to let go of stress is to get it out. Talking it out with co-workers, mentors, or hiring a therapist can go a long way toward establishing longevity in your career.
If you don't want to talk to anyone, or feel more comfortable writing things down, then use a journal. Write it in as often as you like and ease your stress as you do.
Regular exercise is a great way to relieve stress and increase endorphins. Plus it'll give you the energy to tackle what you need to!