Hello,
Apologies for the inconvenience.
You should not need to recreate your entire website. However, I’d like to understand a little more about how you are trying to implement the Mega Menu and how your current menu structure is configured.
Could you please provide some additional details about the steps you are following and what happens when you set Helix Ultimate as the default template? A screenshot or short screen recording of the issue would also be helpful.
Also, could you please confirm whether you have checked our documentation on creating advanced submenus with the Helix Ultimate Menu Builder?
Helix Ultimate – Menu Navigation Documentation
Once we have more details about your current setup, we can better determine why the Mega Menu is not working without requiring you to rebuild the site.
Best regards