Two Sundays later, he missed a game against the Washington Redskins after becoming so ill that he required transport to the hospital.
"Sitting in the hospital bed, I would throw up, watch the game, throw up, watch the game," he said. "I had gotten to the point where I didn't know how or where my career could have gone."
It was during that second episode that doctors diagnosed the anxiety disorder, after which Brooks faced a different pressure: How would he explain it? He could have said he was suffering from some obscure back injury. If the football world knew the truth, his life could be even tougher.
"I was given two avenues -- I could be honest why I missed those games, or make something up," he said. "But I wasn't going to lie. At that point, I didn't want to have anything to hide."
So, even though he said he was literally shaking, he faced the media and told the courageous truth. What happened next stunned him like a safety blitz.
The tough NFL embraced him, opponents quietly coming to him after games to share similar stories. The tough Philadelphia crowd empowered him, fans leaving notes of encouragement for him in the lobby of his apartment building.
"I had no idea it would have the reach it did," Brooks said. "You'd be surprised how many players are going through the same thing. Then there were people actually coming up to me on the streets and talking about their own anxiety."
Many of his teammates rallied around him, many of them feeling free to express their own fears.
"We have lot of respect for Brandon. It took a lot of courage to come out and say that, it took a lot of humility. Most guys would have just made something up," Eagles offensive lineman Stefen Wisniewski said. "The way he's handled it is really impressive."
Not all of his teammates were supportive. Brooks said some still don't understand, wrongly thinking that he just needs to toughen up.