Let's start with basics.
To keep it simple - if you want to gain weight you need to be in calorie surplus. I'll guess you are 6 feet tall, rough estimation of your TDEE (calorie you need for maintainning weight) is 2715 kcal per day. To gain pound a week you need calorie surplus of 500 kcal, which puts your energy demands around 3215 kcal. How much fat and how much muscle you would gain, depends on several factors (genetics, training, hormons, rest, etc.).
I would suggest eating 3000 kcal per week and to track your progress. One very important thing here - like i said, this TDEE is rough estimation, and your actual TDEE can be as slow as 2500 or as high as 3200 (if not even higher or maybe even lower). To be sure about your TDEE, you'll have to learn your body and for that you need time and bodyweight scale.
Also, note that with gaining extra pounds of lean body, your TDEE will go up.
The second thing you need to learn is to keep your eating diary. And by this I mean - "I ate 200g of milk and 120g of eggs". If you say - "I ate 2 eggs for breakfast", it doesn't mean anything. Is it 80g of eggs, or is it maybe 140g of eggs? What kind of eggs (chicken / goose / etc.). Kitchen scale is a must!
After you learn to count weight of your food, use online diary like Cronometer or Myfitnesspal (just to name few) and track both of your macronutrients and micronutrients.
The next thing which you should improve is to set your protein intake at 1g per pound (in your case minimum of 150g of protein per day). Fat shouldn't be lower then 50g (below 50, you might experience lots of problems connected with hormons, like unable to get erection), 100 is even better. Rest carbs.
To give you better picture, if your calorie intake is set at 3000kcal, 150g of protein equal to 600 kcal, 100g of fat equal 900kcal, which means you should take 375g of carbs (1g of protein and carbs = 4 kcal, 1g of fat = 9 kcal).
When you say protein shake, I guess you mean whey powder, right? Drink it only in the morning with your first meal and after workout. Whey is a very fast protein (to keep it simple, I'll call it "fast protein") and around lunch there is high chance you'll still digest proteins from earlier meal. If this is a case, whey will be turned into glucose (sugar).
All in all, until we see your precise food intake (measured in grams), there is not much I can tell you more.