Were you ever tested for the thyroid antibodies, TPO ab and TG ab, to determine if Hashimoto's Thyroiditis was the cause for you being hypo? If you are not familiar with Hashi's, it is caused by the autoimmune system identifying the thyroid glands as being foreign, for some unknown reason, and producing antibodies that attack the thyroid glands. Over some extended period the glands cease to function, resulting in the need for gradually increasing amounts of thyroid meds to offset the loss of natural thyroid hormone. If Hashi's is involved, then that could be a reason for you needing increased meds.
Based on your symptoms, and your FT3 and FT4 levels, it appears that you need to have your meds increased. Just because these test results are within their reference ranges does not mean they are adequate for YOU. The ranges are far too broad for that to be the case. A good thyroid doctor will treat a hypo patient clinically, by testing and adjusting FT3 and FT4 as necessary to relieve symptoms, without being constrained by resultant TSH levels. Symptom relief should be all important, not test results. Test results are important mainly as indicators during diagnosis and then afterward to track FT3 and FT4 levels as meds are increased to relieve symptoms. At your next appointment you need to find out if your doctor is willing to treat you clinically as I described above. If not, then you will need to find a good thyroid doctor that will do so.
I think you can get a good idea about clinical treatment by reading this link. It was written by a good thyroid doctor for patients that he consults with from a distance. The letter is sent to the PCP of the patient to help guide treatment.