I am struggling because of stocks

The stocks I've been holding for the long term, following John Lee's advice to invest in value, have dropped by half.
I feel terrified every time the market opens.
My wife and sister-in-law went from being over 50% in the green to being down 30%.
My son and daughter cut their losses on stocks that were down 70% and moved into Hyundai Motor and Hynix, but those have also dropped by half.
They are plummeting terrifyingly again today.
I'm usually the type not to get shaken by most market dips, but lately, I'm having a mental breakdown.
Is everyone else still holding on??