OP what is it about labelling things as sexual assault, rape and abuse that you are so afraid of?
You've basically already told us on this thread that you want to leave. And it sounds like if the council would give you a house tomorrow, you'd tell your husband you weren't happy and you'd go.
But you don't want to go to a refuge, seemingly because of what people may say when they find out and that it would mean applying the label of "abuse" to his behaviour.
What is it about doing that you're so keen to avoid, and why?
It doesn't really matter about the label. You don't need to label what he did last night as sexual assault, if you find it difficult. It's a shorthand for describing what is happening to you. You can simply say, to yourself, WA, whoever, "my husband touches me and grabs me sexually when I don't want him to and he won't stop when I tell him, therefore I am not happy and I'm leaving".
You seem to be stuck in your head that you are only "allowed" to leave if it's "really" abuse, and you're going round in circles trying to figure out of what he's doing is abuse, because if it's not then you "shouldn't" leave.
You're battling the wrong issue. The issue isn't what label to apply to his behaviour. The issue is you're unhappy because of how he treats you and you want to leave. That's perfectly valid and it's what you should be focusing on. For now, forget the labels and the stigma you feel is associated with the labels. The labels don't matter. Start planning your escape.