YANBU the hysteria here is laughable. I don't know anyone in real life who is 'panicking' about Brexit. Most people I know are level headed, sensible, normal people, who know we will be FINE! Not like the batshit fruit-loops you get on the parallel universe of Mumsnet.
The UK coped quite well before we joined the EU and we will cope VERY well after we leave, (which cannot come soon enough frankly!)
I had to hide a thread last night too. The posters on it were fucking batshit. Coming out with gems like 'I sobbed today with FEAR over Brexit,' and 'we had to prepare for MANY YEARS for the millennium bug, so we need to prepare for the mass fallout of BREXIT; underground bunkers, stockpiling tons of dry, non-perishable food,' and 'I fear for the future of my children!'
Bonkers. Utterly. Fucking. Bonkers. 
How do these people get through a day? Serious question.
As a few posters have said, it is scaremongering, pure scaremongering, and it's pathetic. The only 'food shortages' will be because of hysterical numpties going batshit over Brexit stockpiling food!