yup. You are not eating enough...PERIOD! The number one reason people don't grow is they are not eating enough.
a protein bar between breakfast and lunch? I'm assuming you start school around 7:30ish? You eat breakfast at 6:30? 7:00? And lunch is at 12:25? That's 5.5 to 6 hours between meals and you think you cannot possibly eat any more because of that little 3oz. protein bar you're "stuffing" into your pie hole at 10:15? Come on.
As for shakes, I would say you need more of a meal replacement style (high calorie, high protein, high carbs, lower fat). You don't know how to eat. You need to start counting calories, grams of protein and grams of carbs. Number one goal is to make sure you are getting 2.5 grams of protein per pound of bodyweight. Number two, since you are VERY active, you need a LOT of carbs...so count carbs. Try to get in 1000 grams of carbs/day. Not too worried about fats, just make sure you get them. Don't eat carbs and fats in the same meal if you can help it. You said you take fish oil? Keep taking it. Add a couple tablespoons of olive oil to your nighttime casein shake (no carbs in that shake - except the small amount in the milk if you mix it with milk).
Damn, there's so much more too. Just eat the fuck out of everything. Eat every 2 hours...EVERY TWO HOURS! EAT EVERY TWO HOURS! Did you get that part about every 2 hours? You're eating for function, not enjoyment or taste or anything else. You've got a big job to do and a short time to do it in.
I'd like to see what these strength trainers have you doing too. I'd recommend a Bill Starr 5x5 for what you're doing and your goals. It's a program designed for football players in mind. Main thing is PROGRESSION. Do you keep a logbook? A journal of your lifts? What lifts you did, pounds moved, # sets, # reps, etc.? You should be!! How else will you know if your lifts are progressing or not? Weight is something that can be measured. You want to increase your weight moved on each lift each time you perform it. Even if you only put 5 more pounds on the bar, you are progressing. You need to get serious about this instead of looking for the easy, shortcut way of steroids. You will short-change yourself ultimately if you start juicing now.
Get back to me with some answers to these things.