What should I do?

So I'm having a very hard about how I feel about my training lately. I feel like I've plateaued since I always try to excel quickly in my training but it's been months since I've learned something new. I'm current one belt away from my apprentice black belt after our grading a few weeks ago and I haven't learned anything new. It's really irritating. I do work as an assistant instructor for the dojo. And I feel like if I were to suddenly vanish and quit I would really be disappointing the children since I noticed how much they look up to me. Which I think is the main reason I haven't quit. I'm currently thinking of trying out other martial arts because the thing that interest me most is learning more about the martial arts and become a better. Which I just don't feel like I will get any better at the moment. My family actually thinks I'm being taken advantage of for how much I do and not really getting anything in return. Which is a little annoying but I really don't need anything since I enjoy spending classes with the other students but not as much anymore since my own progression seems to have stopped. I would really appreciate someone's insight on all of this.