If your food is good, you should be fine. When I'm feeling sick I usually switch and eat alot of soup, and other 'comfort' foods, so I just pay attention to calories. There's no reason to stress yourself with too much exercise when you have a cold. One week off will not hurt you. It's the week after.
So commit to taking care of yourself today, and getting back to it when you feel better. OR find an alternative that helps you feel better - walk a bit, at a slower pace, just to keep moving.
Oh! and beware of liquid calories like OJ.

Have nice hot tea instead. Ginger or lemon zinger or something. If you must have OJ, get a lower-calorie alternative and give yourself permission to get rid of it when you your symptoms improve.