I rarely had a problem with all of my deaths being dumb luck, and I usually do really well. (See below image, I go as GunWolf.)
http://i24.photobucket.com/albums/c17/G ... inated.jpg
If you want masochism is CoD4, play through the whole game on veteran.
Unfortunately, I haven't played since I got TF2 and reinstalled BF2. I probably suck now, and I probably won't touch the game again.
I understand your pain, I have been killed by random grenades across the map before, but I usually have enough time to react thanks to the warning system.
In short, if you really want to stop playing, get Team fortress 2.
In fact, if you want to stop playing any thing at all, get Team Fortress 2.