ANA can be elevated in cases of auto-immune thyroid disease. Would document thyroid antibodies and look carefully at the TSH result as the best indicator of thyroid status. Lymph nodes in the neck can sometimes be enlarged with Hashimotos (auto-immune thyroid disease leading to Hypothyroidism), but this would not account for groin nodes. Your symptoms are suggestive of hypothyroidism, but could also be due to other conditions.
Yes, fatigue is a hypo symptom. I also have to lie down and take frequent naps....I am not on optimum treatment yet. Did you have the thyroid antibodies tested to see if you have Hashimoto's? Positive ANAs can mean you have another autoimmune disorder, but it can just mean you have Hashimoto's, which is autoimmune hypothyroidism. Also, especially need to get Free T3 and Free T4 tested. They are the best indicator of thyroid hormone production. Get TSH tested, too, to use as an indicator of thyroid dysfuntion. Range of 0.3-3.0 is considered normal now, but for women need to be below 2.0. However, this is just a guideline for the TSH, and should not be used to determine how well you are doing. Usually, getting the free T3/4 into mid to high range of 'normal' will eliminate symptoms. Get your adrenal glands tested, too.
Go to StoptheThyroidMadness.com to read about proper testing and treatment.
Ask for a ferrtin test.
Low ferritin levels can also cause fatigue and muscle/joint pains.