This is a topic that comes up from time to time, but not started by the usual OP for this topic.
As has been discussed ad nauseum, penis size has absolutely nothing to do with general life success, with a few exceptions:
Was trying to edit and ran out of time...damnit...
1. You have some sort of body dysmorphia that causes you to believe that your endowment is a curse that has affected you overall life quality and confidence level (this is a real condition and in a number of cases requires therapy to even be able to regulate and function in society)
2. You have been able to parlay an above average endowment into business and/or political favor (unethical business practices, casting couches, sleeping your way to the top)
3. You are able to monetize your endowment in some way (porn, cam shows, modelling)
With #3, it should also be mentioned that an above average or larger endowment is not specifically necessary, though it may act as a shortcut. There is a niche section of people that want to see smaller endowments, cuckold or SPH, and things of that nature.
As far as the OP's question is concerned, I have two jobs/careers. In neither one of them has my average endowment ever come up in discussion, not even outside of the workplace. My income by myself would put me in the lower middle class for my area, and my combined household falls solidly in the middle class. I am not married or partnered by choice.
In my younger days I did have numerous self confidence issues due to several factors, not just endowment, but as I got older, I realized that none of it really meant anything.
Don't worry about what everyone else has and just live your life.