Donald Trump’s former press secretary fired back at Laura Loomer after she tried to fat-shame her. Stephanie Grisham was quick to correct the right-wing activist who tried to troll her over her appearance at the Democratic National Convention, RadarOnline.com can reveal. The heated social media exchange started after Loomer, 31, shared a photo of Grisham, 48, speaking at the DNC. Loomer wrote: “Stephanie Grisham really hit the wall. Another traitor who got rich off Donald Trump and then turned on him on J6. I guess she started eating uncontrollably ever since she quit Trump. “She must have gai…