Please visit an apple store to sort this out. Bring you proof of purchase for maximum help.
but i have now a new password for my itunes account, but the id doesn't know that its been changed and still requires the old password which i don't know?
hi, its the same itunes account, but a different password that i cant remember
What you describe is impossible. You can only have one password per Apple Idt.
Here is what I assume.
You created a new apple id. You can have as many as you wish. This isn't the problem and irrelevant to your problem.
You need to use your old account. You forgot the password. Try typing in our old appleid here and request to reset the password.
see forgot my password:
Apple - My Apple ID
You can signout on your idevice an apple id.
setting > iTunes & App Store
You Apple Id is in blue tap on it.
Tap on sign out.
Write all you passwords and accounts on a piece paper. Secure.