That was a mistake, and it was retracted. False on both counts. You are not Catholic. You have not the remotest notion of what the Church teaches, or why. You may succeed in deceiving yourself, but no one else is fooled.
Fasting on Friday by eating fish instead of meat used to be mandatory and now is voluntary.
Was eating meat on Friday a mortal sin in the past? Yes.
Is it mortal sin now? No.