Oh you can definitely fix it, but it takes time and effort, finding the solution. Iodine is one part of it.
Hypo thyroid; all your symptoms point to it.
My hair was thinning badly before iodine, but all restored, my hair is as full as it was in my teens.
Talking about teens; I see hair thinning all over now, even in the young ones. Fluoride etc, I suppose.