I hear you. Baby-steps. All about baby-steps. My big problem was they were thinking that part of my left quad had 'died'. Even with muscle-stim, it would not flex - twas why I was in PT for four months. Now, I have a real quad, all nice and rounded, that will flex on command
But in the beginning, my leg lifts had roughly a 10-degree droop. Every commercial on TV, time to flex and hold the quads, squeeze them til they felt like they would lift off my leg and tear - for me, that and getting to zero were my fights... I used to sleep with a rolled-up towel under my left ankle, trying to make the weight of my leg bring my knee to zero. It felt like it took forever, but now, I can snap a zero-degree perfect leg lift and hold it for multiple minutes with nary a quiver! Baby-steps, it'll come...