I'm 17 and at this age you can imagine how important this is for me and I feel rather embarrassed asking but why is my genitalia so small will it grow?

Small Genitals. This phenomenon may be a condition that can be treated with hormones. I am very happy you were brave enough to bring us this question. May we encourage you to get to a good pediatrician or urologist to determine what they can offer to help you normalize or feel normal.
Depends. If you are normal it might grow more. But if you have hypogonadism or human growth hormone deficiency it will not unless they are replaced on time. Go to the dr.