Hi Christine,
I know it can be very discouraging when you work so hard and don't see results. The cellulite will likely not disappear but you can certainly work on the muscle below it to make it appear smoother.
I know you said you vary your workouts but maybe throw in something totally different if you can like some tabata/ spinning/ gliding if you have access to this.
I love heavy weights and when I tried Mindy Mylrea's booty camp and gliding workouts I was shocked how sore I was and realized even body weight workouts can be effective. Spinning works on strength/ cardio/ core if you have a spin bike. Or even try something other than Cathe like Zuzana Lights workouts - she has lots of free videos on youtube and works you really hard in a short amount of time - good to finish you off after your regular workout!
Diet is always key as well so maybe try take a closer look at your intake and type of foods you eat.
Try not to despair. I wish Cathe was on the forum more to give advice.
Good Luck,
Jamie