At your age its pretty likely that they'll want to wait to see if the gyne regresses naturally, so be prepared for that. You'll need to get blood work done; you're at your hormonal peak so if you get the physical side sorted by op you are way more likely to suffer regrowth if your hormones are out of whack - I stress I'm not a doctor so this is NOT medical opinion, just what seems likely to a logical mind with an interest who has researched the condition. Please get a qualified medical opinion.
You have to be realistic, and a surgeon will want to see a stable condition before operating - i.e. something that hasn't changed for some time. You are still growing, and your body is still changing.
It's not a case of waiting until it gets really bad, more a case of waiting until yoiu are sure it is there for good and not just a transient hormonal response.
As Glinja says, your best course is to go see your doctor asap.