Synthroid and lack of energy

I am a female and was diagnosed with Hashimoto's three years ago (looking at old childhood photos I've probably had this all my life) and have taken Levoxyl and Synthroid in escalating doses over time. Initially 25mcg for about a year and that was the endo plan until bloodwork indicated a need for more. I quit taking it after a year as it seemed I was gaining weight. After a few months went to a different endo and he started the treatment again with 25 (I weighed 160 at the time) and now has worked it to 100mcg (I now weigh 178!!!). I thought that with the higher dose I would have more of a weight loss effect (definitely not weight gain) and thought I'd have more energy, better brain function and happier outlook. I am experiencing the complete opposite. The last time I visited the endo and he looked at my weight gain he just said to "stop it". I work out almost every day for 45 minutes to 2 hours, have a job that at times requires arduous work, I eat a very healthy diet full of fiber, low in fat, low in carbs. I'm always hungry and feel like eating to make up for a lack of energy. I come home from work exhausted. This isn't living. I've had it with the Synthroid and any form of T-4 alone. I'm going to see a natural healthcare professional to try Armour because none of the medical doctors I've seen will prescribe it or synthetic T-3.