What is a normal thyroid level?

I SWEAR that I have a thyroid problem. My Ob/Gyn did a blood test and referred me to my doctor. She said that the # was abnormal. Everytime that my doctor checks it he says that it is normal. Last time it was 3.5. Is that normal? I have the following symptoms:
Cold hands and feet
A tendency to feel the cold
Depression
Tiredness especially in the morning
Headache
Constipation
Swollen eyelids especially in the morning
Loss of hair
Dry skin

The dry skin is particularly bothersome and I hate the hair loss. I am ALWAYS tired and seem to gain weight no matter what I do. How do I make my doctor listen to me? Should I see an endocrinologist even though my doc thinks that there is no problem? He has no explanation for my symptoms and tells me simply that my thyroid was normal at 3.5.