I've been married for just over 22 years. What you are going through is very common, and probably one of the most common causes of divorce. I'm not saying that to be mean or blaming you or your husband for anything, I just want you to understand it is a very serious situation. Be very clear with you husband on why you don't want to have sex, but you must do it in a way that is in no way blaming him. Tell him you are just too tired, and if he could take a few small things off your shoulders, you would have more interest in sex. Then you MUST follow through, even if you are still too tired. As time goes by, he will start to see the cause and effect. Make wife less tired and stressed,,,more sex. Also understand the differences between men and women. Many men, especially when young, will have a sex drive stronger than anything short of basic survival. Where women typically need security and love more, and that usually doesn't change much over time. Where his drive will diminish as time goes by. I wish you the best. I was a lot like your husband when I was young, and as time has passed, those drives have switched. Not that it has really changed, just my views towards sex have changed.
Normally each person needs sex. Talk to your husband about what you want. For example if he wants sex ask him to massage you first so you can relax and enjoy the game. The point is communication and mutual understanding.