Hi Lainey 717!
I don't know if this will be of benefit to you or not, but have you tried interval training and strength training? I know I've been reading a lot about interval training, especially, and how when folks have plateaued, it can be very effective. It involves high intensity bursts of cardio throughout your workout. Also, since we are losing muscle mass, and muscle burns more calories, even at rest, adding strength training and building muscle mass is supposed to be a catalyst as well. I have been PONDERING both of these concepts, but have not IMPLEMENTED either as of yet!
If you decide to give it a whirl, let me know if it helps!