So finally, after 5 pages of comments, you've admitted that you've already spoken to him about his awful habits and hygiene, why on earth couldn't you have said this in the first place OP, rather than dragging it all out. It now seems clear to me that this relationship has run it's course. Not unusual for people who get together when they're young, as you're not truly the person you're going to be, until you reach your 30's, by which time you've had some life experience, and have usually pretty much worked out where you're going in life and who you actually are. It happened to me too. I met my ex when I was 15, we got married just before my 18th birthday, had our first baby when I was 20, and then over the next few years lived a pretty good life, no shortage of money, no arguments or fights, but we just gradually changed as people, and at age 32, I woke up and realised that he was no longer the person I wanted to spend my life with. We talked about it, and realised that we no longer wanted the same things from life, so separated and went our different ways. I've since remarried, and have been happily together with my new life partner for more than 30 years.
So, it's time for you to accept that it's over OP. If you've already told him about your concerns with the way he looks and his appalling habits, and he hasn't seen fit to do anything about it, then I think I'd be inclined to write him a letter telling him that having spoken to him on numerous occasions about his lack of personal hygiene, etc., which he's failed to act upon, it's gone on for so long that it's gradually given you the total ick, and you have now reached the stage where you no longer fancy, or love him, so the relationship is over. Leave him to read it, at which point if he cares at all, he'll probably tell you he'll change, etc., but all you have to say is, 'sorry, it's too late, you should have listened to what I was telling you in the first place, so now it's over, end of!' No need for you to feel guilty, it's obviously his own fault for not listening when you've tried to tell him the way you felt, and maybe, if you tell him that that's the reason you're leaving, he might just wake up and do something about himself, and who knows, he might even find someone else who will love him, but your time together is well and truly over in my opinion.