I feel your pain. Your account of fast and steady weight gain sounds all to similar to my thyroid issues.
All I can add is, my success came only when I let go of weight and focused on health.. I could not control my weight. I could not control my hormones. I could only control my choices.
I chose to eat healthily on a daily basis. I chose to exercise 5 days a week.
I learned I was MORE than a number on THE machine. I learned I was MORE than a number on the tag of my clothing. I learned that WHO I am is a matter of how I think, feel and act. It has nothing to do with my size..
Hang in there, RMS. Take control of what you have control of--your daily choices. Let go of what is beyond your choice/control.
I hope a complete thyroid panel--TSH, free T4 and free T3 was included in your recent blood work.