Have enlarged heterogeneous thyroid, tsh was normal.suffering w/hypothyroid symptoms.endocrinologist said "impossible" to be thyroid.need 2nd opinion?

No: The endocrinologist is correct. Your thyroid function is normal, your symptoms have another cause.

Prob normal: Remember, diseases cause symptoms, but having a variety of symptoms doesn't necessarily mean you have that disease. If your testing was normal, then you need to look for another cause to your problems. However, make sure your lab was not only "normal", but appropriate for your age group, and those numbers may be slight different. Consider endocrinologist if desired.