If you find yourself feeling overwhelmed, don't panic. This just increases your stress levels and makes life even more difficult. So:
TAKE DEEP BREATHS. Stretch the tension out of your muscles. Energise your system with a brisk walk. Before returning to your desk, distract your mind with a paper or magazine.
BREAK DOWN TASKS into bite-sized chunks. Each should take one or two hours' work at the most.
PRIORITISE EACH TASK. Rate them according to how they relate to your main goal of the week.
REVIEW YOUR RESOURCES. List the hours you have available and the potential help you can draw on.
DROP, DEFER OR DELEGATE as many tasks as you can before making a step-by-step action plan