Looking at old pictures of my bf, I don’t recognize him anymore

He gained a ton of weight, and when I look at old pictures of him it makes me sad. He used to make me have butterflies, he used to treat me better, he looked so much healthier and handsome. Obviously I love

Him, but I don’t get butterflies. He has a hard time losing weight. It’s been years. What do I do? He always mentions breaking up with me would make him lose weight. And I’m the reason for his weight gain because we always eat together.