I'm 18 5'9 and my penis hasn't grown! It still looks like a baby penis! I cannot pull fire skin over the head! It's about 5.5 inches erect and about 1 inch wide! I can masturbate! And clear sperm comes out! I do masturbate often! Is it why? Should I stop? Please help!

No your penis is this size because of DNA and genes, there is nothing you can do, that will effect its size

The only people who cares about penis size is teen age boys in locker rooms

Clear semen (not sperm) is normal enough, and varies by age, by how often you ejaculate, and many many other factors. It is more common before puberty. If you feel that you don't have all the characteristics of an adult yet, see a doctor to measure your testosterone. But if you can masturbate a lot, you probably are producing enough.

To the OP, 5.5 inches is average.