Question: when was the last time you took a break?
Legs respond to high reps/sets? I wouldn't set that statement in stone. Especially when there are so many factors that dictate how a individual should train (no matter what the bodypart).
I've been training legs via higher volume of sets - not reps. This is due to the fact that we train legs specifically once every week. And my goal is to increase my leg strength/mass. Training with just high reps wouldn't do that for me; so we fluctuate. Somedays, we lighten the load (on squats) and work on explosiveness. But our reps never travel above 12.
That's something you could do: work on explosiveness. I don't know what you've been doing for your legs. I'm assuming squats? Have you tried any of the other squat variations?
And now that I look at the time...is this a waste? You're probably training right now............