I see this as mostly an (and I recognize it as a real) issue caused by other men and patriarchal society. Most women care about penis size way, way, less than men do. It's a problem primarily of you guys own making.

I was recently with a man who had a rather small and low circumference penis. After the initial surprise, which I kept to myself, we did just fine and had a really sexy time together. If he'd been apologetic about it, or acted nervous about it, it might not have gone so smoothly. Just own what you have and if somebody is rude to you or rejects you for it, fuck them. Too many guys think their dicks are somehow magic, particularly if they are on the larger size. A smaller man has had to learn how to sex up a woman without relying on that, and it tends to make for a better experience for the woman, which unless she's a size queen, she's going to truly appreciate.