It's definitely fair that most self-image conversations are around how it is shaped for women right from childhood. Women definitely get the worst of it. However, that does not mean that it does not impact men.
The link between self-image and sexual problems may seem tenuous at first but if one looks at the science then it is much more obvious. The two biggest sexual problems that men face--erectile dysfunction and premature ejaculation--in a significant number of cases have psychological factors at play.
The biggest one is size. Some boys start bragging about their size pretty much within a year of hitting puberty, and some of them never stop! And there is never a measurement game. No validation of the claims.
It is important to understand that the top-down view that we get (typically) of our penis tends to underestimate our own size, while the side-on view (fleeting glance, rather) that we get of other people's penises--say in a changing room, in a hostel, or in a urinal(!)--tends to overestimate their size.
And then, along comes porn, and created absolutely crazy expectations. We forget that porn stars have been chosen to be outliers on size instead of their acting ability or their personality. Using their size as the index is mathematically unsound, but almost impossible not to!
So, for a lot of men, sets in place a downward spiral of confidence.
In bed, feelings of self-doubt that have been acquired over several years manifest themselves in anxiety ("I will not be able to get it up"), and inadequacy ("let it be over soon"), which are self-enforcing and may lead to actually not being able to get an erection when you need it. Or, coming too soon.
Therefore, dear man, it is well worth your while to use a ruler and measure the length of your erect penis, and use the size test here to know how you stack up.
Only two percent of men who are worried about size actually have a small penis. And for the ones who do have a small penis, it is important to remember that there are other factors to be absolutely mind-blowing in bed. You can read about them here.
Scientific study of penis sizes