I have had gynecomastia for almost 3 years help?

Okay so i am turning 16 in november and ive had gynecomastia since i was about 13. ive read on numerous sources that it should go away within three years. however ive seen to significant changes or improvements. I am not overweight and i go to the gym a few times a week. i do eat unhealthy sometimes but hey who doesnt? i asked my doc a few months back about it she said it was one of the least serious cases of gyno shed ever seen and i should just wait it out. but with this 3 year mark approaching im starting to fear that my gyno will not go away with puberty. it isnt that big of a deal, it can be hidden pretty well with an undershirt alone but it does keep me from going to the beach, etc.. so my question is, is there anyway to help get this gynecomastia to go away? i read if you take zinc pills it can help reduce gyno because they help produce testosterone is this true?