Hello Dr. Rynne. I Have Been Experiencing Extreme Fatigue For

Hello Dr. Rynne. I have been experiencing extreme fatigue for years. I can barely get out of bed in the morning. I was prescribed Cytomel 10mcg daily for my thryroid function, but continue with feeling exhausted all of the time. My recent labs included:

TSH within normal range
Free T3 within normal range
Free T4 low

Would the cytomel put my free T3 within the normal range? What does it mean if the Free T4 is low, but the rest are normal?

Thank you.
~Alicia