This could still be caused by DNS cache. We say it takes 72 hours, but that’s a very rough guess, the majority of people will see the new site within 24 hours, and for the remainder it tapers off after that. But it could take over a week in extreme circumstances.
It could also be possible that you’re unable to access your website for another reason. But to tell more about that, we need more information about the issue you’re having accessing your website.
Could you please describe more about what you see when you try to access your website? Any error messages or screenshots could help a lot.