Don't beat yourself up !! You will NOT derail any of your efforts at long term weight loss or good health because you haven't been able to exercise. Remember, taking care of yourself when you're sick IS every bit as important as getting some exercise. It's all about knowing what our body needs and right now, your body needs some rest. When you start feeling better, you can slowly ease back into a regular routine. Don't try to do too much too soon or your risk staying sick for longer.
Don't worry ! Here's something I learned from my own years of yo yo dieting,"the faster a person takes off the weight, the faster it packs back on. take the weight off slowly and it will stay off". Think lifestyle change, not diet. Get some rest and push those fluids. that's what your body really needs right now.