For how long have you been bothered by constant fatigue ?
Besides thyroid and related autoimmune conditions you are having , fatigue could be caused by a condition called chronic fatigue syndrome.
CFS is a debilitating disorder characterized by extremefatigue or tiredness that doesn't go away with rest, and can't be explained by an underlying medical condition.
As its a broad topic so i would like you to have a look at the following link ,j hope it proves useful;
hope it answered your query.
Feel free to ask any more queries.
Please reward a 5 stars rating if you are satisfied.
You can always opt-out if you need a second opinion.
Please avoid leaving a low rating as it hurts an expert's standing