Hi, with carefully planned diet and 150minutes of exercise in a week should help you lose weight regardless of hypothyroidism. You should seek professional help to understand whats going wrong. Calorie intake has to be less than what you burn, for anyone to lose any weight. Also consider if you are weight cycling, that is, if you have lost weight before and gained it. And this is your 2nd attempt. It will be much harder this time.
Next Steps
Consult a dietitian online or face to face for a tailor made diet regime.