Hey man the big thing we have to determine here is if its gyno or just a fat deposit. Put your hand behind your head and feel around the nipple, really try to get an idea of whats under there between the skin of the chest and the muscle of the pec. If you feel something hard under the nipple that is enlarged glandular tissue, and you've got gynecomastia. If theres no gland it could just be a poor fat deposit, and you can get rid of it by getting really lean.

Theres two options for treatment of real gyno, drugs or surgery. Drugs are much more popular with steroid induced gyno, as the gland is fresh and young and can easily be gotten rid of.

There are two types of drugs to treat gyno, "AI's" like Letrozole work by redcing your estrogen levels to nearly zero, starving the breast tissue of estrogen and hopefully forcing it to shrink into oblivion.

"SERMS" like raloxifene bind to the breast tissues estrogen receptor sites and prevent estrogen from being able to act on the breast tissue and sustain/grow it.

SERMS are generally better than AI's because they have the same effect without forcing you to live without estrogen for a while. Believe it or not crashing your estrogen sucks and has a host of problems, something like raloxifene (the god of all SERMS) will leave estrogen levels intact and only act on the breast tissue.

With all that being said see an endocrinologist because drug treatment is very unlikely to fully "cure" it after having it so long. I was able to help mine with a SERM like drug called epistane after I aggravated and grew it beyond what it already was with steroids. But I could never get it to shrink past what I had at puberty, I could only get it to pre steroid size, the old tissue was just too mature and solid to be affected by drugs. Fight for Raloxifene though, it is safe and WORTH A TRY.

Your final, and most likely only real option for a "cure" is surgery, its fairly routine, they make an incision around the nipple and remove the gland then stitch you back up, 3 months later it looks like nothing ever happened and your moobs are gone. Only downside is its pricey as fuck, $2000-$7000 and unlikely to be covered by insurance as it is cosmetic. Your best bet to get it covered is to say its "painful" and "effects my everyday life", but chances are still slim.

I simplified that as best I could, any most questions just ask I can link studies and stuff on various drug treatments if you want too.