Hey bro, don't feel insecure about stuff like that. A girl who truly appreciates you doesn't care about your size.
As mentioned above, you are NOT at a disadvantage at all. You gotta believe in yourself, and just enjoy your woman.
I had a short fling with a very "experienced" lady, and she told me I was the best she ever had, even though I'm
only average in size. She was not in love with me..... we were really good friends. So she didn't have any incentive
to boost my ego. She basically said my enthusiasm and the shape of my penis were main contributors to her massive orgasms.
She has been with men of every age, color and size, so I trust her opinion.