Hi I do not know what naturethroid is, is it a natural supplement or NDT? If it's NDT I wonder why you are on such a low dose.
I was told by Dr Lowe, scientist never to split thyroid hormone. What you do when you take thyroid hormone is stimulate the receptor sites on the cells. By trickling the thyroid hormone in then you are not "waking up" the sites which need to be stimulated. One dose is the best way. Some people say lose energy as the day wears on but if this is the case it's normally an adrenal problem.
As I said I don't know what you are taking but if it isn't working perhaps you could change to Erfa, this is what my doctor prescribes to people in Belgium.
If you take too lower dose of thyroid hormone you can literally shut the thyroid production down. Most doctors do not know this. eg 50 mcgs of T4 can tell the gland you are getting the thyroid hormone from elsewhere and it will cease to produce at it's normal rate so it is imperative that you always take enough to cover what you are producing and then more. The same goes for NDT, too lower dose can make the thyroid gland produce less, this could be what is happening in you case. Do your pulse before rising to see if it's anywhere near 70.