Without any thyroid function half of a 137 mpg tablet of Synthroid does not sound like it would be adequate. If you have symptoms and want to discuss, please tell us about those and also list your thyroid related test results and reference ranges shown on the lab report.
Agree with Barb here.
The a1c of 5.9 gives you an average blood sugar level of about 130.
This alone warrants further investigation by your Dr.
A normal A1c is < 5, with average blood sugar of 100, or a bit lower.
If addressing blood sugar with diet, look at lower carb, and add in exercise. Get a blood sugar meter and test how high you go about 1 1/2 - 2 hours after eating (maximum should be < 140). Lose weight if overweight.
Further, if your thyroid is out, it also can exacerbate blood sugar problems.
Your A1c indicates pre-diabetes. You'll need to make some serious diet and exercise changes in order to prevent it from becoming full blown type II diabetes.
The TSH over 3 would point to Hypothyroidism (Low thyroid or more simply "Hypo")
This would warrant at best further testing of thyroid. Specifically demand to be tested for Free T4 and Free T3 tests. Be very specific with the word "FREE". It is NOT about the cost of the test. Rather it is noting a specific test that counts the hormone that is NOT attached to a protein. And thus "free" meaning all by itself. This is important because ONLY the "free" unattached hormones are used by your body.
If you do not specify "free" then you may get "total" test which is obsolete and of limited value.
What are your symptoms? how do you feel?