Small penis for un-erected, or is it because I juke to much?

Hey guys, I have been reading some of these questions on Men's Health about peoples penis sizes, and most of em are like 13, 14, and they have like 4 inch un-erected penises and what not. My un erected looks really small, I haven't measured it, but it looks like 2 inches at most. I have like a big penis when I am horny though, and I heard the max a penis can erect is 2.5 inches, but mine seems to grow larger than that. I'm 15 years old. Another thing, might it be because I jack off too much, like I do it 2-4 times a day. I wanna cut it down, but it's hard to. Also, one time I didn't jack for a week, and my penis was that much bigger, a lot. So I have two questions, is my penis small or un-erected because I jack off to much, or just naturally. And, does jacking off 2-4 times a day make your penis smaller for the time being? Like say if I stopped for a week, it would be bigger then it was a week ago because a lot more *** and blood could reach the penis?