Can't add Outlook account to Xfinity email

I've always connected all of my various email accounts (GMail, etc.) to my Xfinity account so that I can get all my emails in one place. Two days ago, my Outlook 365 account kept telling me it couldn't connect because my "credentials" weren't correct. I deleted the account after several attempts to connect and being told my password was incorrect. And now when I try to add the account, I get that same "wrong password" message. But I know I'm using the correct password. I can't configure manually as I once was able to do, either. Suggestions?