This video can help you change your password in TurboTax Online. You can try again with that. 

How do I change my password in TurboTax Online?

If that doesn't work, you can contact our support team and share the screen with them for the best help.
Here is the link for you to contact the support team:  Contact Us

If you require further assistance please contact our phone support team or contact us directly on Facebook or Twitter.

Thank you for using a TurboTax.