What Causes Persistent And Grey Vomiting?

I drank last night and threw up four or five times today.. That has been happening quite often in the past few weeks when I drink but never happened to me before, which is weird to me because I am going through the same rituals and whatnot surrounding my drinking. I am 22 years old, weigh in at about 220 and am 6 foot 2 inches tall. No medical history really I am just worried something is wrong with my insides. The vomit started as regular vomit then turned to a gray liquid and then stomach bile.