Hypothyroidism and weightloss

I have hypothyroidism and I was just put on medication to manage it. I'm overweight and trying to lose some lbs but I just seem to gain more weight when I eat healthier and exercise. If anyone has any tips on weightloss with hypothyroidism I would greatly appreciate it I'm feeling so defeated like my body is betraying me no matter how hard I try. So any tips would be wonderful thanks