Discipline, and keeping constant watch on hormone levels. See a dietitian. Talk with your endocrinologist and dietitian and pcp and get them to work as a team. It’s not easy, it takes a lot of work, A LOT of work. TRACK everything, I mean everything you put in your body.
I have hypo and the only thing that really works for me is plant based. I was 263 pounds and went plant based I got down to 187 in 7 months. It takes so much discipline. I have been bad the last couple months and gained 15 back so here I am going back to my healthy diet.