Nice to hear you are slowly finding a way out of your issues!
I am glad you are giving iodine supplementation a chance, did you consult with your doctor about it and about the dosage?
6,25mg is half Iodoral tablet (at least at the standard strength), it is a tiny amount (average Japanese diet is double of that iodine x day) but often it is better to start low and build up progressively with iodine because it might give unpleasant side effects (like nausea, headache and such).
Iif you are taking such a tiny dosage because it gives you side effects I just remind you that a smart strategy is to take a tiny amount two or even more times a day.
As your thyroid improve the side effects will gradually disappear, you should be able to take 4 or even more full tablets at once without any discomfort (not that you have necessarily to take such big amounts of it but just to underline the point).
Let us know how you progress, it might help others in your same condition too.
If glycine helps you don't worry about dosage, 3g is tiny, 5-10g is still very conservative, it is a quite easy going amino acid very unlikely to give issues even if heavily overdosed.