
To not practice on your own vastly limits your physical ability to master your body. In essence all, martial arts come down to this: the ability to see a technique in your mind, to feel the technique in play, and preform the technique physically. All three parts must act in concordance. You get this primarily though countless hours of solo practice. The solo practice, even if it is just the simplest actions of your art inform your body and link together your physical movement with your ideal thought. This is of course not mindless repetition, this is thoughtful intentioned action. Each action must be formed in your mind. Each part of your body intentionally driven though space and time to conform to that though. The intention and care is key as, without them, you are just exercising. There are more effective methods for getting fit. Without the solo practice you will never get beyond the most basic level of competence.
Your instructor cannot make you learn. This is a hard concept for some people to understand. You are paying good money after all, they should be teaching you! Even the best instructor can only show you a tiny fraction of the things you need to learn. An analogy I have seen is that a good instructor can show you one corner of a darkened room. They can turn on a little night-light for you so you can stand in the corner and see. Then they can point to the darkened room and say go that way to find the rest. Lighting the rest of the room is your job, not theirs. Perhaps with decades of instruction they can show you a bit more of your art, but largely your expression of the art is unknown to them. It is your art to master and they don't know what it looks like ether outside of the broadest of strokes.
You must explore that space. Do this by finding limits to your ability and narrowing in on better. Expose yourself to ideas, even if they seem silly at first. Listen to people who are on the journey talk about their exploration. Begin reading and understanding how to mentor and teach others. Mostly remember that almost all of the effort and learning you must do is yours and yours alone to find and accomplish.