There are many schools of thought on this subject, first are we talking micro p***s or bigger, It would have been nice if you had put an erect size in, as they say 4 1/2 inchs is the average, you can find this out on altp***s.com, you could start jelqing to help incress you size, just go to pegym, they have a beginners page, but please this is not a quick fix, its slow but will work, but just take it slow and do as they say.
Good Luck
The size of the penis doesn't matter, it's what you do with it.
It depends on what your wife needs to be satisfied. I think that you are the only one how should know that.
I don't mean to be mean or anything but honestly, If a women really wants you size of your penis it's not important at all. Personally, if I could choose I wouldn't like my husband to have a small penis. It's actually not about penis it's more about confidants. So my advice is even you you don't feel act confident.