Sorry for the reason you're here but, glad you found us.
You are very correct that something is off because people who have optimal levels don't have thyroid symptoms.
Your labs show room for improvement.
Most people do best when their FreeT4/T3 levels are around 60-80% of range. Some people (such as myself) need their levels even higher to be symptom-free. A few might need them slightly lower but, very rarely, below mid-range.
That said, your FreeT3 level is actually 37.5% of range and your FreeT4 level is 57.5% of range.
Now, please know that Synthroid is a T4 med. If our thyroids/bodies are working correctly, that T4 storage hormone will get converted into T3, the active hormone.
If conversion is appropriate, the FreeT3 and FreeT4 levels will usually be within 10% of each other. You can see that there is a 20% difference between your levels with your FreeT3 being the lower percentage.
The simplest (but, possibly short-term) solution would be to ask your doctor for a Synthroid dose increase. This will increase your FreeT4 level and hopefully increase your FreeT3 level (via conversion).
One strategy that has worked for me in getting dose increases has been to point out to the doctor that the FreeT4/T3 levels are well within the normal range and could increase and still be within the normal range.
I suspect that you might benefit from some T3 in the form of Cytomel....or a switch over to Armour which contains both T3 and T4.
If you can't get your doctor to agree to a Synthroid dose increase, I suggest looking for another one.
You could call local pharmacists to get contact info for doctors that Rx Cytomel and/or Armour. Doctors that prescribe these T3-containing meds are usually more thyroid-savvy. Be sure to speak to the pharmacist and not the counter help. Don't give up if the first pharmacist doesn't help - just move onto the next one on the list.
Please let us know how things go.