I'm 16 and concerned about my penis length?

Im 16 about to be 17, and I have huge self esteem issues when it comes to my body. My stomach isn't as flat as i want it and my face is a little round, but that is all managable, ive been losing weight recently. But my penis is always a scary issue for me. I have never really measured it, i know that my iphone 5 with it's case is about 4 and a half inches with a ruler (even though google says its 4 inches but my ruler said 4.5) and my penis full erection is a little longer than it, maybe half an inch but im not sure. But it looks so small to me, and im so scared to show it. And this girl i like who i might date is scaring me to death for when she might see my penis, im so scared. Only one girl has ever seen my penis, and she said it was average size but i use it well. But please, it is on my mind all the time, is there any hope of my penis getting bigger? I tried jelqing for a month straight and followed a routine, but it didnt grow at all, and it was a hassle to do. I'm just scared.

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