Do Plyometrics, stretching, and do a handstand on a wall. Blood flow to the brain as well as produces that growth hormone.

Try testosterone as well.

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I am around 5' 6" and a half, though I am still going through puberty.

While I cannot tell you anything that may already know, I hope you know that the above info will help you out. Also, I would recommend meditation if you could and possibly into raja yoga. Raja yoga is to learn to control the mind, for control of the mind leads to control of the body. It's going to take maybe a decade or so for this one though.