OP, you appear to have all the drive and enthusiasm you need to go all the way with this flying thing, all that is required is a touch of patience. Some aspects of flying can only be learned by repetition, and that takes time. You have plateaued because this is a stage in your flying where you simply need time in the cockpit for everything your instructor has taught you so far to come together.
Trust all the other PPRUNERS and I when we say just relax and enjoy your flying, and it will come in good time.