Boy troubles

My bf and I have been together over a year and by now he acts like he has no one to impress anymore. He skips showers occasionally, I havent seen him in anything other than shorts and a wrinkley T shirt in forever, he eats straight junk food(he's gained a lot of weight in the past 6 months), and he hardly ever shaves unless i ask him to (it would be different if he had a full on beard but its just patchy stubble). Like I still love him and all, but I wish he cared about his appearance. He has a lot of stressful things going on right now, but sometimes its even hard to kiss him. How do i hint to him that he's being straight up gross?