Signs and Symptoms of Thyroid cancer?

I'm sorry that you've lost so many members of your family. That is always difficult, and makes dealing with our own health issues rationally somewhat harder. My sister passed from esophageal carcinoma, with me at her side, so I do understand a bit of what you've been through.

At the same time, please know that a huge percentage of people have thyroid nodules found - and only about 10% of these nodules will ever be thyroid cancer... so it is quite possible that you have a benign process going on.

In most of us, there are absolutely no symptoms. Our hormone levels are usually normal (and your symptoms sound like yours are probably not - if you search under "Graves disease", or "hyperthyroidism', you will likely see many of the symptoms you've described.
http://www.endocrineweb.com/hyper1.html
http://www.nlm.nih.gov/medlineplus/ency/article/000356.htm
http://www.merck.com/mrkshared/mmanual/section2/chapter8/8d.jsp

Hyperfunctioning nodules, again, usually benign, could cause these symptoms, too. But the only way to determine this accurately is to have your blood tested (TSH, T4), and possibly to do a fine needle aspiration of the nodule.

Please don't be too concerned right now - you are doing the right thing by having this investigated. With treatment, it is likely your symptoms can be resolved. Here are some websites that you may want to take a look at:
http://www.mythyroid.com
http://www.endocrineweb.com/indexpg.html

Hope these help. All the best to you.

there really are no signs in symptoms of cancer but some of the problems you're having sound like hyperthyroidism and possibly a thyroid storm and possible a light stroke or very very high blood pressure but here's signs and symptoms of hypo and hyperthyroidism and thyroid storm
hypothyroid

Fatigue, exhaustion, depression, moodiness, sadness, difficulty concentrating, difficulty remembering, sensitivity to cold, cold hands and feet, inappropriate weight gain, or difficulty losing weight, dry, tangled or coarse hair, and hair loss, especially from the outer part of the eyebrow, brittle fingernails, muscle and joint pains and aches, tendinitis of arms and legs, carpal tunnel syndrome, plantars fascitis - sole of the foot pain, swelling or puffiness of eyes, face, arms or legs, heart palpitations, low sex drive, infertility, recurrent miscarriages, heavy, longer, more frequent or more painful menstrual periods, high cholesterol levels, especially when it’s unresponsive to diet and medication, worsening allergies, itching, prickly hot skin, rashes, hives (urticaria), chronic infections, including yeast infections, oral fungus, thrush, and sinus infections, shortness of breath, difficulty drawing a full breath, constipation, neck feels full or sensitive, raspy, hoarse voice
low basal body temperature below 97.8 to 98.2 degrees in the morning

hyperthyroidism

nervousness, irritability, nervousness, or panic attacks, difficulty concentrating, short attention span, palpitations, irregular heartbeat, high pulse and heartbeat, atrial fibrillation, feeling hot, sweating more than usual, hand tremors, diarrhea, fatigue, dry skin, even thickened patches on shins and legs, fine, brittle hair, infertility, periods are lighter, less frequent, or stop altogether, muscle weakness, especially in the upper arms and thighs, eye problems, including double vision, scratchy eyes, bulging, sensitivity to light

Thyroid Storm

Some people with Graves' disease or hyperthyroidism -- an overactive thyroid that is producing too much thyroid hormone -- develop a condition known as thyroid storm. It's not common however; only 1-2% of patients with hyperthyroidism develop thyroid storm. During thyroid storm, the heart rate, blood pressure and body temperature can become uncontrollable high. Whenever thyroid storm is suspected, the patient must go immediately on an emergency basis to the hospital, as this is a life-threatening condition that can develop and worsen quickly, and requires treatment within hours to avoid fatal complications such as stroke or heart attack.
Risks for Thyroid Storm
Untreated Graves' disease and/or hyperthyroidism is a particular risk factor, as is being female.
Even when the Graves' disease is identified and being treated, however, certain other factors raise the risk of thyroid storm:
Infection: lung infection, throat infection or pneumonia
Blood sugar changes: Diabetic ketoacidosis, insulin-induced hypoglycemia
Recent surgery to the thyroid
Abrupt withdrawal of antithyroid medications
Radioactive iodine (RAI) treatment of the thyroid
Excessive palpation (handling/manipulation) of the thyroid
Severe emotional stress
An overdose of thyroid hormone
Toxemia of pregnancy and labor
Symptoms
What are the symptoms of thyroid storm?
High fever of 100 to as high as 106
A high heart rate that can be as high as 200 beats per minute
Palpitations, chest pain, shortness of breath
High blood pressure
Confusion, delirium and even psychosis
Extreme weakness and fatigue
Extreme restlessness, nervousness, mood swings
Exaggerated reflexes
Difficulty breathing
Nausea, vomiting, diarrhea
Recent dramatic weight loss may have taken place recently
Profuse sweating, dehydration
Stupor or coma
Thyroid storm is treated with a combination of antithyroid drugs, blockade iodine drug, beta-blockers, and treatment for any underlying non-thyroidal illness or infection that may becontributing to the thyroid storm.
NOTE: If thyroid storm is suspected, go to an emergency room immediately!