Do you have inflammation on your penis? If you do, that's more of a concern than the size of your penis right now.
Do you know what's causing the inflammation? Have you seen a doctor?
Good advice from auntiejessi. Also, how old are you? As guys go thru puberty, the penis begins to grow larger, but not all guys develop at the same rate - one guy could be pretty large already at 12 or 13 & another might not start growing till 14 or 15, so you might actually still be within the normal range.
Also, what is causing the inflammation? Guys of a certain age may find themselves masturbating excessively or too forcefully, which obviously could cause inflammation. But if you can ‘fix’ whatever’s causing inflammation, I don’t think it would inhibit normal growth - in fact, even if you DON’T fix it, I doubt it would affect development...