Thanks for your question.
Yes, the thyroid hormone level can fluctuate within normal range.
This is due to the timing of the blood draw & also stress associated with those times.
Your symptoms may be related to your anemia.
Another strong possibility is underlying depression.
Please treat your depression.
Drink plenty of fluids & dietary fibers ( miralax, fibogel, citrucel etc.)daily to normalize your bowel movement.
Then get yourself checked out for autoimmune diseases like connective tissue disorders, lupus etc.