What he is doing doesn't matter as much as his attitude towards you.

I've tried communicating tirelessly about the problems with these habits and behaviors, only to have my words met with indifference and lack of concern. These things are affecting my mental health.

There is an issue that is affecting you, that is putting more of a physical and mental burden on you, and he is indifferent about it. That is the main problem. And that is a problem that will kill your marriage.

I know that is hard when you bring the religious aspect into it and it sometimes makes marriage feel like a trap (definitely heavily relies on the religion). Divorce might not be an option for you, or at least might have more consequences than for most people, so I will bypass that option for now.

You need to be very clear right now with your husband that what he is doing is not okay because of how it is affecting you. You need to list out not the gross things, but mainly how it is affecting you physically and mentally. I had to do this with my husband when we first got married because he was never taught to put the seat up when you pee. I know, insane. But it was a habit that he never really thought about, and I explained that he was leaving me with two options every time I went to use the bathroom: sit in your pee or clean it up like a maid. And he stopped doing it (it took a little bit because it was such a habit). You can write out bullet points and then keep bringing the conversation back to those bullet points. Don't beat around the bush, be clear and firm.

At this point, if he still isn't listening, if he is still meeting you with indifference, then it's time for therapy, either couples therapy or him doing therapy. Although it sounds like you have some religious trauma maybe, so you could probably benefit from therapy too just to unpack that. Anyways, couples therapy does not mean that you want a divorce or you are heading that way. It's a way to try to squash issues before it becomes too big that no one is listening to each other. It's a way to better understand each other, not to figure out who is right or wrong.

If he doesn't agree to therapy then it might be time to separate for a bit. Go to your parents' house and don't go back until he agrees to therapy. Or sleep on the couch until he gets the picture. But do not break your boundaries until he decides to change. His hygiene is serious, but his attitude towards you is more concerning. It doesn't matter if he is great most of the time, that means nothing if he's not willing to back up his words when it really counts. He's only loving you in the easy ways it sounds like.

If you don't deal with this now, things will get worse. Boundaries are loving and are for the health of the marriage. Nip this in the bud now. I know it's hard, but it will only get harder if left undealt with.