For penis size : There is no medi(tab， cap， powder，oil，pumps，rings)in the world could increase length &  girth(motai) of penis. Even if spending lacs of Rupees. Size of penis is not imp. for satisfctry sexual relationships.  For this one should hv a good firm，hardness in penis & should tk sufficient time bfor discharge. Hv good sleep，do exercise & yoga daily 1 hr.  Tk hot milk 1 glass mor & eve Tk tab. Manmath Ras & Pushp dhanva Ras one tab. each mor & eve for 3 months. See the results orelse consult a sexologist personally.

Usually increase in penis size is required  in very few cases. One has to learn good sex  with regular practice with permanent, supportive  partner ie. Usually  wife. So if u r unable  to perform satisfactorily with casual  partner, nothing  to worry, it's common. If u r married  & unable to perform good sex with  ur wife  , better  to consult an expert  at pune.

You should see a Urologist who can help allay your anxiety regarding the same. Normally there is not kuch change with what you are born with, but still only after examination can this question be answered.