Partner seems uninterested

Lately my partner seems so turned off by the thought of sex when usually I’m the one trying to keep up. He’s been more stressed lately but I thought he would be more enticed by the idea as a kind of stress relief but it seems to be completely opposite. Any advice on what I can do to get him more interested or should I just wait until he initiates the whole thing? He has never turned down sex until recently and I don’t know what to think. Thanks ladies 😘