Iodine labs are sort of bogus. If you have not been using iodized salt or taking vitamins with iodine, you are deficient. You need about 1 gram of iodine in your thyroid.
Your low body temps really suggest a functional thyroid problem, which can be low fT3 and/or fT3 is been blocked by rT3 which typically is a result of adrenal fatigue, which doctors do not believe exists.
More info here:
Start taking 4000-5000iu vit-D3 before your lab work.
Hypothyroidism can lower T levels and correcting thyroid levels can sometimes reverse T level losses in younger males.