Hello
I have gone through your question and understood your concern.
You didn't mention your exact
thyroid disease.This is an important element to understand better your actual situation.
Anyway i can say that the most common cause of
hypothyroidism is Hashimoto's disease also called Hashimoto's
thyroiditis.
In people with Hashimoto's, the immune system attacks the thyroid.
This can lead to hypothyroidism, a condition in which the thyroid does not make enough hormones for the body's needs.
Yes,it is correct.This is a lifelong disease and for this reason you have to take the thyroid medicine lifelong.This is vital for your well-being.
Your difficulty in weight loss,depression and extreme fatigue are symptoms of hypothyroidism.
I can say without doubts that these symptoms will disappear and you will feel much better after some weeks of thyroid
hormone replacement therapy.
So,after your thyroid tests will be normalised,with an healthy and hypocaloric
diet plan and with more physical activities you can reduce your weight.
I suggest to stay in contact with your treating
endocrinologist for the follow up of your thyroid disease.
After 6 weeks of therapy it is recommended to repeat the TSH test and accordingly to do the necessary dosis adjustment of Levothyroxine(the thyroid medicine) .
Hope i have clarified your doubts.
If you have other questions,feel free and ask.
Best regards.