Bro, I'm glad you've managed to find a husband who is totally cool with all that, but for most people the expectation for a date is best foot forward. This means washing up, dressing nicely, and in general treating it like it's a special occasion. If someone doesn't do that I'm likely to assume either indifference or that they are putting their best foot forward and are less put together normally. It's no different from cleaning your home before bringing someone back to it the first time. It says "I cared enough to clean up, and I don't live in filth or a massive mess"
But additionally, it is absolutely sustainable to change habits for what people find attractive/tolerable. Sure if something makes you miserable it isn't, but plenty of changes for others aren't ones that make a person miserable and absolutely can be sustained.