I tried logging into my battle.net account but my email is supposedly no longer associated with the account, neither is my phone number. However the account still exists as my friends still have it added. Help?
It sounds like your account was compromised and the person who did it changed the email (which means they are in your email account) and the phone number.
Either that or you just forgot which email you used That happens too.
You can put in a ticket to CS and they can help you find the account and regain access. It may require submitting a Govt Issued ID though so be prepared for that. They delete it once the account ticket is done.
Start here with a ticket to help recover the email address. That will help you figure out what happened. Contact Support - Blizzard Support
And here is how to submit ID if they ask (and they will). Providing Government-Issued Identification - Blizzard Support