If you pitch well, it doesn't matter what size you are. So focus on what you can control - your pitching.
That said, I personally was only 5'9" at my high school graduation, just having turned 18, but grew to 6'0" in college over the next two years. There is a medical term for this late growth - don't recall the name - but it is hereditary.
My son just turned 15, and is almost 6'0" and 175 lbs. He started his growth spurt when he turned 14. He is now catching up to many of his tall friends, who had huge growth spurts starting at 12. In your case a lot will depend on what stage you are in your biological development, and other factors: How long have you been at 5'5"? Were you taller than your peers at younger ages? How tall are your parents?