I know that dealing with an acute illness like an Influenza illness is much easier than coping with a chronic illness. Getting the flu is difficult to endure but at least the illness is temporary and you will get better.
You can also get the flu vaccine once you recover to limit the chances of developing the illness again. I always have my children get a flu vaccine because if not they will get sick a few times a year because of germs that are spread at school.
With a chronic condition like diabetes, the HIV illness, or cancer they are usually conditions that you treat for the rest of your life and some days are worse than others. There are many people that live with diabetes and live normal lives eating sugar free foods and monitoring their blood sugar.
HIV and cancer are also manageable depending on the stage of the disease. The nice thing is that with advances in medicine many people diagnosed with HIV are no longer subjected to a death sentence as many people live with the condition for decades without succumbing to the disease.