The whole point of PHs is to lift heavy and grow. You aren't going to get size or power if you are lifting low the whole time, making your PH useless, which is another reason it would be best if you do what triton suggested up there ^^^^^^^^ and avoid the PH for now. You still have plenty of time/room to grow and such without using a PH. You aren't at a plateau, no injury stopping you. You just have to keep doing what you are doing since you are still growing.
EDIT: And by injury, joints mainly.