I think 6 is a good rule of thumb. Sometimes 7 maybe. Like in addition the the normal 3, you might have another one between breakfast and lunch, plus before workout, after workout and bedtime.
It's kind of hard to say exactly how much you should eat. If you were an adult, I would think 2500 calories at the right ratio would be about right for now. Since you are still growing, you are likely to need more than that. Since you are thin, try 3000 calories and see what that does for you. You aren't prone to fat gain, so going high like that should be a good strategy for you. If you eat that much every day, I am positive you will grow. You are going to want 150 grams of protein per day at a minimum. That is 600 calories, leaving another 2400. Eating more protein is certainly ok. You are probably going to want about 1500 calories worth of carbs (375 grams). Then fill in the rest with fats. But it doesn't have to be that exact.
So say you go with 7 it might go something like this
1: 2 servings of oatmeal and 2 eggs
2: 2 servings cottage cheese and 1 scoop of whey
3: 2 tuna sandwiches and a banana
4 (preworkout): slice of whole wheat toast with peanut butter, 1 scoop whey
5 (postworkout): 1 scoop whey, something with 60 grams of simple carbs, like a weight gainer with dextrose or just some chocolate milk
6: chicken breast, brown rice, a couple green veggies
7 (bedtime): casein protein shake, maybe some cheese
Thats just kind of a rough example. It should be somewhere around the 3000 calorie mark depending on portion.
Your parents are going to be like "Damn that Ironman! We don't want to buy all that $h1t!" lol
But if you eat something along those lines you'll grow for sure.
How's the workout going? What did you end up deciding to go with?