Sleeping Upright

After using this App for years, I was prompted to Login to the app. That’s never happened before. So, I tried to do so, but it wouldn’t/couldn’t recognise my Apple account details. I then tried using those details to login. Wrong details. Attempted to have a link sent to update my password - no email sent! I tried to get a little help from Support, but I need to have my login details for the site to do so. Talk about the circle of doom. Can someone please tell me why this is happening and that after years of carefree use, I was prompted to login? I still can’t use the App, by the way. Send hel