Seek a Consultation. At 19, adolescent gynecomastia should have resolved. If the size is persistent and bothering you, consider seeing a board certified plastic surgeon in your area with experience treating male breast enlargement. Surgery is the best option in most cases. http://www.drmele.com/sanfrancisco-gynecomastia.html.
Time for consultatn. About a half of males will undergo a transient nipple/breast enlargement at he onset of puberty. Normally it will resolve slowly as other hormonal changes kick in over about a year. Carrying around extra weight can aggravate the issue as fat can masquerade as breast tissue. If persistent after 2+ years i would consult with a cosmetic surgeon about tissue removal ; localized liposuction.
Gynecomastia options. Gynecomastia can be pubertal or adult type. Once medical causes for the problem have been eliminated or treated then a fair number of patients are candidates for surgical correction. See a plastic surgeon in your area and s/he may be able to better guide you better re options specific to you.