Sex life is boring

I’m just frustrated and tired of mediocre sex or lack there of . My husband has gained a lot of weight ( working on it ) and I’ve never missed an opportunity to support him and tell him he’s handsome, I encourage his fitness and support him with healthier eating habits but not in a demeaning way. Im always in the mood for him and I always express that. But intimacy has just been a downward spiral for us and it’s starting to make me feel resentful. It doesn’t even seem like he’s trying no matter how many times I’ve tried to address that. Its been a year now . I ’m so frustrated and now I’m starting to feel like I’m not good enough . What to do?