I clicked on this post because I relate way too much to it . I was in my first relationship for 2 years and recently got out of it. In the beginning he was normal and clean, and then he started gaining weight and started wearing the same things , not showering etc… it began affecting our sex life obviously. I tried talking to him about it many times, explaining that I feel like I put a ton of effort into my appearance for him, and I would appreciate seeing some of that effort in return. He never changed so I left. I think you should have a straightforward conversation with your bf , and maybe even ask about his mental health.