"The amount of people saying "why didn't you say no?" "Why didn't you stop him?" Etc is appalling! "
I think it is actually quite unusual for someone in a normal, loving relationship to feel unable to say no actually. Op describes him as communicative and supportive, with no hint at abuse in their seven year marriage.
I'm not saying it wasn't upsetting for op, but I think it's entirely normal for a man to approach his wife in this way, and entirely normal for her to say no thanks.
As op says she usually makes it absolutely clear when she's not interested, I think it's plausible that he simply misread the situation. I bet there aren't many women who, when their dh makes it clear he's in the mood, thinks 'I'll just lie here until he realises I'm not enjoying it.'
Eventually of course he got the message and now, after being told, even implicitly, that he sexually assaulted her, he has backed right off.
I don't think op is wrong to feel how she does, but I don't think he's necessarily wrong either. To me, it is misunderstanding and misjudging a situation. As your relationship was good until this op, I would suggest some honest conversation in order to resolve things.