Tim might have negative mother issues.
A male with this kind of issue has often problems trusting others or is scared of losing somebody. They tend to feel hopeless and helpless and to have aggressions. It's not rare for those men to have depressions and they tend to some way of self-harm, be it from drugs to cutting. (There is more to this topic, but if you want to know more I suggest you to do some research on your own since this is a kind of complicated topic.)
Why'd Tim have this?
Because his mother send him to this asylum when he was very young. Tim lost his mother figure, if he didn't already before, and was lacking one from then on. Also, in my opinion some of those described feelings are fitting into his profile: He does seem to be depressed and he is often hopeless. He definitely has trust issues and after losing Brian and Jay, everything went down. And although it is not shown so often, he has some aggressions, too. I mean, in the entry in which Jay wanted to tell him about everything, Tim punched him in the face. Or when he saw Jay's corpse in his living room/kitchen, he yelled at the hooded man that he'd kill him. And there are some more examples, too.
YOU ARE READING
About Stone Bees [a Marble Hornets Fan Book]
RandomA fan book for Marble Hornets! Contains stupid things, Brim, a stick in the mud, the loop of unhappiness, probably gay shit and Alex, the douchebag. Oh, and maybe everything else from Marble Hornets! Edit: many short stories at the later chapters...