Speaking as someone whose thyroid levels were technically within the low end of normal, push back on that if you still feel like shit. I'm on the lowest possible does of Synthroid, which pushes me up from borderline-low to middle-of-normal, and it makes ALL the difference in the world. My cholesterol levels went back to normal, my skin isn't dry and fragile any more, and a bunch of other little "Oh you're just getting old" problems magically cleared up. :P