Apple Id not signing into or changing on phone

So I changed my apple Id on the computer oping it would sync with my phone. It changed my email address on my phone but when I look at my Id name in settings it still has my old email. Now it is requesting I use the password which is new as well to sign back in. The problem is that it wants me to still sign in with my old email and not the new one and doesn't pick up any of the passwords even for my old email. I have tried to change my id on my phone but it won't accept any of it...please help I don't know what to do