21, Low Testosterone

What is your iodine intake? Post body temps, see the link.

Hair falling out is a symptom of hypothyroidism. Is your neck thick where your thyroid is?

That is the only lab work that you have?
Example: Vitamins and Supplements Rooted in Science - Life Extension

Take fish oil.
How much vit-D3 are you taking.

Growth stopped: Any blows to the head or whiplash preceding that?