First thing: stay calm.

Second thing: don't stop researching, but stop diagnosing yourself. The only way you're going to be fully informed is to research and ask your doctor questions. Write down all your questions and take them to your next doctor visit. Make him answer all of them and don't let him dismiss you.

Third thing: Thyroid disorders are very treatable.

How did your sister do after her surgery? Have you talked to her and asked her questions?

The fact that you have multiple nodules rather than just one makes it less likely that it is cancerous. Have they done any blood tests to check your hormone levels? Most people who have nodules don't have abnormal blood tests because the nodules themselves don't produce hormones or alter the thyroid's function in that way.

Some of your symptoms may be due to your stress and the fact that you are looking for something to be wrong. Wait for the scan and see what it says. Your doctor may want to biopsy the nodules to see if they are suspicious. Don't worry, the biopsy (with a small needle) is not as bad as it sounds. If it shows nothing, they'll want to wait and see if the nodules grow. You will probably have another scan in 6 months or a year.

If you are having trouble swallowing, ask the doctor if it is related. If the nodules are pushing on your airway or esophagus, the doctor will probably advise you to have them removed regardless of whether they are suspicious.

Personally, doing research actually made me worry a lot less. Words like "nodules," "growths," "surgery," and "cancer" all are really scary. But if you really look into what these mean in the context of your thyroid, you'll see that it is likely that it isn't cancerous and the prognosis is really good if it is. Look into your options and ask your doctor about them.

All the best. Feel free to write back if you have more questions.