Why was Holden "sort of crying" when he left Pencey?

At the beginning of The Catcher in the Rye,Holden Caulfield has been kicked out of his third school for failing classes, and he has a few days before he's expected home. Rather than wait until he is scheduled to go home, he spontaneously decides to hop a train to New York, get a cheap hotel, and wait until his parents get the news before showing up at his home. As he is packing to...

At the beginning of The Catcher in the Rye, Holden Caulfield has been kicked out of his third school for failing classes, and he has a few days before he's expected home. Rather than wait until he is scheduled to go home, he spontaneously decides to hop a train to New York, get a cheap hotel, and wait until his parents get the news before showing up at his home. As he is packing to leave, the stress and reality of the situation start to sink in. He becomes very "lonesome" and can't stand waiting for the bad news to reach his parents. He also starts thinking about his mother. He packs a pair of skates that she bought for him, but they are hockey skates and he wanted the racing variety. He says at this point, "Almost every time somebody gives me a present, it ends up making me sad" (52).

Holden is sad, lonely and facing more shame about being kicked out of Pencey. All of these emotionally charged factors are bound to overwhelm a guy at some point. He describes his exit as follows:

"When I was all set to go, when I had my bags and all, I stood for a while next to the stairs and took a last look down the goddam corridor. I was sort of crying. I don't know why. I put my red hunting hat on, and turned the peak around to the back, the way I liked it, and then I yelled at the top of my goddam voice, "Sleep tight, ya morons!" (52).

Holden doesn't have a best friend, a reason to stay, or a reason to go. He can't stay at school and he doesn't feel like he can go home. He's probably feeling scared about the future and fearful for the consequences that await him. Holden cries because the seriousness of his school situation, his frustrating life, and his feelings of depression and loneliness all crash down on him at once.