Hello,
Why did not you use child theme for additional customization?
Never change files of the parent theme. Use child theme for these purposes.
Anyway, even if I enable parent theme I don’t see any Account icon in your header, single product displays fatal error https://prnt.sc/26cfsdt So, old theme is not good for you. Do you have backup of you site before the update? Could you, please, create a staging site and restore backup there to understand changes you made in the parent theme and move them to the child theme of your production site?
Regards