I would say what we have here is a classic case of "The grass is always greener on the other side", but the issue is actually far more complicated. Because of the mentality of our society--"Bigger is better" or more in general is better--and man found to be complaining of having a big cock is seen as a whiner, regardless of whether his qualms are legitimate or not. On the other hand, underhung individuals such of yourself have your feelings of inadequacy compounded by a society that says you're not good enough and had been taught to pity you as lacking.
I must admit, I'm guilty of this pity toward smaller guys, but I'm doubt m stopping because it doesn't help. It only reinforces the idea that a small cock more of a disability than it is.
If we're being honest, then let's be fully so. I have a big dick. Great. It does nothing to help me do my job out keep my grades up, doesn't make me a better person, and is not some gift from God or nature. You have an average dick from what I can see--call it small if you want. It may affect your relationships with women or men who are unable to fully think outside of themselves and see it only as an obstacle or a liability, but it does not debilitate you. It does not detract from your skills or talents that actually contribute to your survival and well-being or that of society.
Does size matter? Of course it does. We're human: we attribute meaning to everything. Should you let it hold you down or back. No.