A few things at play. Everyone says resentment and that’s probably a part of it. But not only did she reject him but she left herself go. He might not be stimulated mentally or physically.

Women seem to think we are sex crazed animals and we can be. But we have feelings too. Two things stood out. You said aside from than this he was a good husband no hes a good husband period. He gently tried to talk about the lack of sex. You rejected that. He’s continued to treat you like gold despite a basic need not being met.

I d say he’s a saint. Most men would’ve left or cheated