The ranges for the tests are as follows:
TSH Sensitive (0.34 to 4.82) and for FT4 (0.59 - 1.17)
Just checked some old lab results of mine - I am hypo, but in contrast to you, when I was first diagnosed, my FT4 was 0.71 (higher than yours or at least in the same ballpark, since our tests were probably done by different labs), my TSH was through the roof at over 57! In my case I have anti-thyroid antibodies and my body is attacking my thyroid gland, and my pituitary gland works fine. Like I said I suspect you may have a pituitary issue but regardless of the cause of the FT4 level, with that level, you could be considered hypo and your symptoms are in line with that.
Do you know what the lab ranges are? 0.68 for FT4 would be considered low with the ranges my lab uses - 0.90-1.60. For any range it would be on the very low end. Usually if you are hypo (low FT4) due to a problem with your thyroid, your TSH would be high, but instead it is quite low (probably within the normal range but on the very low end.) Low TSH and low FT4 usually indicates hypothyroidism due to a problem with your pituitary gland, rather than true thyroid dysfunction. Your pituitary gland puts out TSH (thyroid stimulating hormone) to stimulate the thyroid to produce its hormones (which would be the T4.) It looks like maybe your pituitary gland is not functioning properly and putting out too little TSH, resulting in too little T4 - or, it is on the very edge of doing that but borderline normal.