My account isn’t working at all.

I honestly don't know what's going on with it. I'm expecting a very important email and I can't access my account on both my laptop and my phone. I've already tried the Wi-Fi, going onto data, I even changed my password and it's still not letting me in. My iPhone 6s lets me in but I cannot receive any new mail. I can see old mail but I'm not getting anything newer than the 18th of November. It tells me that the user name or password is incorrect and since the email is definitely right as I've checked it five times and I just changed the password and that didn't help either, I'm really stumped. My laptop comes up with an error message telling me that the page cannot be displayed after I put in the password and sign in. So if someone can help me fix this, it would be greatly appreciated.