These symptoms may be due to side effects of THYRONORM
The best would be to reduce your dose to 37.5 mcg and then see the response.
If your symptoms go away,it will prove that these were because of THYRONORM.
Then after few weeks you may increase the dose to 50 mcg.
If your symptoms persist inspite of reducing the dose,then the cause is other than the THYRONORM and in that case you have to consult a doctor for it's diagnosis and treatment.
In any case don't stop THYRONORM of your own and discuss the matter with your treating doctor.