Eat a shit ton of food and hit the weights hard and heavy 3 times a week (no more), and you'll gain 20-30 pounds so fast people will think you're on steroids. You may have 3 years of messing around half-assed in the gym, but you don't have 3 years of dedicated, serious lifting.
I'm 6'2", and when I was 165 lbs (many many years ago) I looked like an Auschwitz survivor. And I was about 6-7% bodyfat with a 29" waist...and STILL looked skinny. So yes, you look skinny.
You need to eat about 2-3 grams of protein per pound of bodyweight, and add 4 tablespoons of Extra Virgin Olive Oil (EVOO) to a protein shake (no carbs) about twice a day. Other than that, eat whatever. D0 a 5x5 style training along with that and you'll gain a bunch of weight.