So Foggy found something terrifying in Matt's desk drawer. Something that made him lose his balance, flashback to all his worries about Matt's "put on a happy face" campaign, and look like he was having a heart attack.
So what did he find? What could Matt be hiding that would freak Foggy out that much? Given the severity of the reaction, I think we can safely rule out the possibility Foggy found where Matt hid all his junk food. It could be some leftover memento of Matt's time possessed by a demon, whatever that would look like? How would I know, I didn't read Shadowland?
What? I should? How dare you threaten me with such a suggestion?
Back on track. Could be Matt was able to figure out which set of remains were his father's after all, and he's keeping his dad's skull in his desk. Or what he thinks is his dad's skull. Maybe it's drugs. I kind of like that idea, if only because it gave me a picture of that Green Lantern/Green Arrow cover, with Foggy saying to Daredevil, "All right Hornhead, you've always got all the answers. What do you say to this?" Then a shocked Daredevil exclaiming, "My alter ego, Matt Murdock, is a JUNKIE?!"
Well, I thought it was funny, if nonsensical.
Matt hasn't shown any signs of thinking he and Daredevil are two separate people, which is something at least. Although, given the flashbacks Foggy had to Matt saying he didn't care if Foggy thought he was in denial, of Matt saying he hates the old, angst-ridden Matt, of Foggy thinking Matt would never react this way, has Matt brought back one of those other identities. Mike Murdock? Jack Batlin? Maybe he's getting ready to ditch being Matt altogether, because it'll be easier to be Daredevil and some other guy, than Daredevil and the guy lots of people think is Daredevil?