Our problem is less with Gynecomastia and more with Ignorance of the condition.
At 17 and with an absence of body hair, I'd suspect that you are not yet fully through puberty. Puberty is a process that takes years. since you appear to be still in that process, It is still possible that your breasts will diminish over time. That possibility less a less realistic hope as time passes.
To be a really good surgical candidate, you should be fully through puberty in any case.
17-5=12 yrs old at onset, like me. The Doctor (not aware that the condition runs in my family) Said to wait a few years and it would 'Go Away'. I'm 68 yrs old now, and still waiting. Actually, the surgical procedure was not available when I was younger so I had no alternative but to learn to live with it.
Gynecomastia is defined as: Any visible or palpable enlargement of the breast in a male of any age or a female prior to the onset of puberty.
Using that rather liberal definition, about 2/3 of the male population has gynecomastia.
On some men, the breast is one of the first places where fat is deposited and for some men, the last place where it can be lost by dieting. Exercise has no effect on gynecomastia.
Since I have had it for such a long time, and it runs in my family; I accept it as an unwanted and embarassing but normal condition.