I think you're being overly sensitive to violence, but to each his own, it's just that I've never found anyone else who'd react like you towards a video game, most people just despise it. I've never seen anyone get sick or vomit because of it.
For some reason I don't really understand, while I'm perfectly comfortable with (and even enjoy it immensely sometimes) gory and ultra violent games, I can barely stand looking at real life gore. I won't vomit or pass out, but I do feel very uncomfortable and even a bit of dizzyness, depending on how shocking said gore is. Heck, I was watching a video of Dir En Grey (a Japanese metal band) which had a lot of disturbing imagery, not only gore, and I couldn't stand it past the first minute.

tl;dr – I didn’t get into games until I was 15 and npcs were starting to look more like humans than cardboard cut-outs. I’ve got memory issues from brain damage, but I still remember the first times I encountered violence in videogames. Seizing a business man in Bloodlines and draining him near death, freaking out, running to the sewers the moment I let go as I realized I hadn’t seen him as a human. The first and last GTA game I played was Chinatown Wars; ran over a person three minutes in, froze, saw an ambulance pull over and turned the ds off. Execution, a flash game, made me vomit.

I’m not an especially emotional person, so that I’m still having issues with violent games makes me think it is an age issue. My knee-jerk reaction is that enforced age ratings are shit, but maybe the lack of lead in, not having digital violence abstracted by older graphics and childhood excitement, is a way to at least slow down indifference?