I don’t find my partner attractive like THAT anymore?

We’ve been together 6 years. Over the years he has gained a lot of weight, he looks unrecognizable. The weight has gone to his face and his body of course. I still love him so so much. But I find it really hard when it comes to sex. It kills me that I feel this way. I hate it. But I have a hard time coming / even getting wet anymore. I just used to look at him and literally melt. I’d be immediately wet just by being around him and he used to put effort into having sex. Now I just get on top of him and do all the riding etc to make him cum. I fake my orgasms 8 out of 10 time. I HATE feeling this way! I feel so guilty that I do. 😪