So i've tried my hand at mass gainers of the sorts, Oats, PB, Choc Syrup, Milk, Olive Oil. Made a 16-24 Fl/Oz glass, not sure which. I got it down but ended up throwing it back up about an hour later? Why? (Also, i'm not a very good eater. I usually only eat when im hungry. Never could put on very good lbs, so i thought shakes might help with my daily protein intake)