Sorry to hear about the trouble. Adobe XD latest update which 28.8 is available for both macOS and Windows so in case if the update is not available on macOS then there could be a different issue which we need to figure out. Could you please launch Adobe Creative Cloud Desktop app and in the app list look for Adobe XD and check if it gives you to option to update or open? If it gives you the option to open, I'd recommend re-installing the application and check again. You can also refer to this help article: https://helpx.adobe.com/creative-cloud/kb/creative-cloud-application-recognizing-available.html
Let us know if this helps or if you need any further assistance.