The definition of gynecomastia is in part: "visible or palpable enlargement of the breast."
With that broad definition, it affects about 2/3 of all males. Welcome to the majority.
Even if the barely palpable (feelable) are not counted, and only those of us who have visible breast enlargement are counted we still are probably the majority of the male population. (Though I do not have numbers to support that statement)
Before you let this eat you up, take a good hard look at the men you see in stores and elsewhere. Our condition is very common. It runs in my family so I have a slightly different attitude than most people about it.
In my case, the surgery was not available until I was too old to care, The surgery requires a skilled hand and may be covered by medical insurance such as you may have from your employer. Some insurance companies will cover the cost only if the surgery is medically necessary. In those cases, reports from an Endocrinologist and a Psychologist may be needful to demonstrate that the surgery is necessary and that there is little chance of regrowth.
Good Luck