Can't sign in to Yahoo Mail

So this has been going on for about three weeks now. I open up Yahoo Mail and it asks me to sign in as per usual. However, even when I put in the ID and password I KNOW are correct, it tells me "Sorry, the page you requested was not found." This happens even when I've tried the homepage and to get Yahoo's help I have to pay them a monthly fee. I already tried logging in through Ymail on my phone and that hasn't worked either. I really don't want to have to create a new email but if I've been hacked I guess that's the only option. Please let me know if there's anything I can do.