Covid oriented. When to do those?

One frightening element caught by my eye is that 48 percent patients complaining of chronic fatigue syndrome after recovery. And 38 percent complaining of chest pains after recovery with some difficulty breathing. If Ct scan of chest is done, scarring of lungs is visible. What is this? Pneumonia signs? Will this scarring go away eventually? And will lungs restore to 100 percent function eventually. Please explain me if this damage is identical to damage caused by smoking. And if I contract covid -19 , what should I do on daily basis during the disease to prevent this organ damage. Some people even go on to say that fatigue syndrome can also last a lifetime and things will never be like before as mentioned on mayoclinic. And at what stage ct is useful. Beginning days of virus. Or in the middle. Or post recovery. Is it to be used for monitoring purpose? And when is the right time actually. are viral markers blood tests any useful? when to do those? I want to be fully competent to handle.