45 [M4F] what's the point?

What's the point in thinking about sex when it's off the table? When your wife is always tired, feeling sick, or has a headache - yet still says "shall we have sex tonight?" at lunchtime knowing full well by 8pm it won't be an option? When you do everything around the house - chores, remodelling, childcare, pet care - while your wife chills out or goes to bed...what is the actual point?