Dear friend GOOD NEWS! U R absolutely NORMAL!! According to a major study 70% of males have erect penis  between 4 (10 cm) and 6 inches long. So urs is within usual range. Now just consider this--- women don't judge u by ur penile length , they need true love, tenderness, care , foreplay much more than the actual penetration!! It's what all studies say, dear friend! So focus on delivering these things rather than the length of ur penis ( which is actually normal). I suggest u relax and if ur anxiety is affecting u , do consult a psychiatrist and a Urologist who will clear all ur doubts!!

Need to be evaluated