Hello and welcome, I just want to say that your doctor is making a big mistake by not trying to find out why you are having those symptoms.
Depression, lack of energy, and gaining weight easy, shows that you have some kind of health problem. I cannot say that it is your thyroid, that could be what is causing the problem.
It might be in your very best interest to search for another doctor. Unless your doctor is willing to find out what is making you feel bad.
Your health is very important, and a good doctor will take that into consideration.