I've Had Most Of My Thyroid Removed 35 Years Ago.

I've had most of my thyroid removed 35 years ago. Have been taking Levothryxin since then. Dosage has never been increased since then. Now I have no energy or stamina, tired all the time. I'm loosing hair in clumps, have thinning to almost non existent eyebrows, but have unusually thick hair on my head usually. My last blood test of thyroid was just barely in normal range... Down from 1.38.....do I need an increase in dosage?