Isn’t in the mood

When my wife is stressed she can’t get into the mood. She said the need and want is there but she can’t actually get in the mood and focus on it. This has become a huge issue in our relationship. When I’m stressed I use sex as a stress relief and she’s the complete opposite. I’ve found myself more stressed, feeling deprived, and wanting sex all the time but getting rejected. What can we do about this? I have no idea how to go about fixing this.