Am I taking enough protein?

Ive been working out for about a year and when I started, I used to take 2-3 scoops of ON whey after my workouts. I realized this is probably too much and not healthy so recently Ive been taking one scoop of whey after my workouts, and then one scoop of casein right before I go to sleep. Is this enough protein (supplement wise). I eat peanut butter, fish, steak, etc throughout the day plus plenty of carbs. Also im pretty skinny, im 5'11 and weigh 146lbs.