Your upper right back muscle. Man, a human back is like a labyrinth of muscles, you have many more than one "upper right back muscle". As for recovery time, that is entirely dependent on which...
**** chalk or straps. A few weeks ago I hit 335x5 with alternate grip, but I ****ed my back up about a week and a half ago and haven't done deadlifts since. :(
Man, I don't even use whey anymore. A 1.5L glass of milk does me just fine as a postworkout meal. Seriously though, your body was spewing broscience out of his *******.