I was wondering why don't you do higher reps on your warm up?
You'll get better pump when you're doing the actual sets.

@kege

Try Leg Press first then Squat for a change. Warm up 2 X 15 on Leg Extension before proceeding to Leg Press. Warm up again 1 X 25 on Leg Press before doing the actual set.

You should add stiff legged deadlift to your hamstring workout. Hams and Quads are different muscle group just like Biceps and Triceps.

Leg Extension is important too. You should add 2 sets of 12-15 reps after Squat and Leg Press.

Friend, you are losing muscles by eating 3 times a day.

In BB you gotta eat 5-6 protein meals regularly. I am currently eating 4 meals daily and I could hardly gain muscles. I need min. 5 protein meals daily to gain muscle mass.