for mass and strength gain is there a huge difference whether u choose to do 3x5, 3x3, 3x4, 2x6, 5x3 for squats?

I have been doing 3 sets of 5 reps ever since i started, but lately on my last few reps, my lower back is so tired that i cant keep it straight anymore (doing kind of a good morning on the way up) no matter how hard i try. I am worried I might injure myself if i keep doing this. I'm wondering if i can change this up somehow by either doing less sets, or reps, or both.