Struggle w/ wt loss and have hypothyroidism. Is it best to follow a certain ada diet to assist with weight loss?

Weight Watchers. If weight is a struggle for you, you may find that the support of a program like weight watchers, overeaters anonymous, or take off pounds sensibly helps you more than trying to stick to a diet on your own. The best diet is one that you'll stick to! you'll definitely want to make sure your thyroid labs are normal so this is not working against you.
Fix thyroid first. First, fix your thyroid with proper medication and dosage. A well-balanced diet and less food will both help. The diabetic diet is generally good but not required.
Over weight & hypoth. Patients with hypothyroidism gaining weight in my experience have to increase the exercise time , adding cardiovascular for at least 45 minutes , 3 to 4 times x week, restricting calories, sugar., check your bmi and start eating bellow 1200 calories is helping a lot of our patients with same problem. Also check with a doc.The thyroid lab for be sure the medication dose is appropriate, & others related.