Can’t log into my optonline.net email account

I think my email has recently been hacked as I’ve been getting emails to reset my Netflix and Spotify accounts. I figured I should change the passwords to everything so I started with my email. I changed the password to my optonline email but then the email stopped working on my phone. I figured it was because I needed to login with the correct password so I deleted the email account from my phone and tried to login with the new password. It then told me the email was invalid. I looked and made sure my server settings were set correctly but still no luck. This is my main email and it would be really inconvenient if I can’t sign in on my phone anymore since I have online school send help lol