I've lost part of my website after updating envato Market

I installed the themeforest Photography theme and built my website www.weddingsbyzest.co.uk about 3 years ago and it has worked really well. A few days ago my Wordpress plugin manager prompted me to update my Envato Marketplace plugin which I did. Since then all of my 100+ pages that were built in Content Builder and password protected have been wiped clean!!

Has anyone experienced this?

Also, no longer seem to be able to use Content Builder when building a new page???

Thank you