Fudgesicle symptoms and conditions

I've been on synthroid now for about a year. My dosage is VERY little (0.075). My doctor keeps running blood tests every 3 months and assures me I am within the "lower-end" of the norm, but I still feel tired, sleep deprived, wake up with night-sweats and I keep gaining weight...

I am only 24 and have just been told that I need to take this medication for the rest of my life, it\s pretty depressing. I keep asking if there are other ways to lose weight and feel more energized. He tells me that I need to keep taking this medication and has put me on a "sleep hygeine" routine where I go to bed and wake up at the same time every day.

Does this "disease" mean I will always be overweight and tired for the rest of my life? I would like to know if someone else with more experience with this medication can give any sort of advice? Feeling a little hopeless about it and not really interested in complaining to my doctor anymore.

Thanks:)