Feeling like I might be dying

Standing on the train, the feeling overcomes me and I have to sit down on my backpack and coat. I took my coat off because I was too hot even though it's barely above freezing outside. The train is packed with people so maybe that's why I'm warm, but it's not the kind of warm I feel in the middle of summer, when it's so humid that your skin feels like a damp towel. No, this is the all-over, uncomfortable heat that comes from illness. I feel like shit, but I can't and won't ask for a seat because on either side of me there are old men sitting in single seats and they have earned those most coveted thrones somehow.
As I walk home I throw up. I'm standing by the side of the road, kneeling eventually, spilling my guts out on the sad excuse for city beautification that houses those upright twigs we call trees. No one stops their car, many pass, to see if I'm okay. What would they stop for? I imagine that a relatively large and fit-looking young man ruining a patch of grass by drowning it in bile is something worth checking out. No one wants to see that. That's disgusting. I like to think that if the passers-by were me, I would have stopped to check up on the lunch-loser.
But I probably wouldn't have.
Once, while walking to the train, I saw a classmate of mine, a girl whom I almost never talked to but recognized from physics, walking in front of me suddenly drop to her knees and put her face in her hands. When I got to her on the sidewalk I touched her shoulder and asked "Are you okay?" and smiled my best grandma smile, sweet and understanding. She nodded and wiped her eyes and I walked on, satisfied with this quick response that somehow nullified the equal quickness of her emotion. If she had been throwing up would I have stopped? Instead of a smile and a hopefully comforting encounter, a horrified glance and an unsympathetic quickening in my step would have transpired, most likely.
I'm getting over my sickness mostly now and the main instrument to my recovery has been the busying of my mind. What an act of kindness does, like laughter, is denote the lack of a threat. When someone makes the world seem kind, sympathetic, optimistic, then pain fades to the background. When the world keeps passing by, pain stays put.