Hello: I'm A 53 Year Old Nurse. Was Diagnosed With

hello: I'm a 53 year old nurse. Was diagnosed with Hashimoto's at 18. I have been on cytomel and synthroid for several years now. I felt much better on the cytomel than just on the T4 alone. Lately I have been experiencing dizziness and lack of concentration but TSH is in the normal range at the low end. T4 is at the high end and T3 is at the low end. Heart is good. Should I consider adjusting my meds again?