Haha yea, just gotta use your power wisely.

Yo dude, sorry to hear about the tough situation. I had corrective surgery for pectus excavatum when I was 14-17, luckily before I'd grown very much. I was able to receive the "Nuss Procedure," where they thread a metal bar under your sternum to "pop" it out, leaving it in for a couple years for your bones to set correctly.
That was the alternative to the procedure you've described, I wonder if your docs have mentioned that possibility? It may not be viable because of how much you've already grown, but might be worth the thought. Both procedures are relatively common and both have advantages, but from everything I've been told/experienced, the Nuss procedure is the more painful.

It's a tough row to hoe either way, but I know you'll come through it. In the mean time awaiting your procedure, it can help -- if only a little -- to exaggerate upright posture as often as possible, throwing shoulders back, etc. Also, working out your chest muscles is a solid way to slow the pectus from worsening (consult the doc first, obviously). Above all else, fight that thing intellectually emotionally? spiritually? with all you've got! You'll beat that shit and breathe easy one day soon. It'll be a wonder to have so much actual breathing room. Your oxygen efficiency will likely have gotten stupid high, then when your air capacity quadruples you'll feel superhuman (after post-op recovery that is). Best of luck, OP.

PS - don't forget to get some quality pics eating cereal out of your chest first. Shit is cash.

I have it, nowhere near as bad as the photos people have linked which is why I havn't pushed to get surgery for it (from what I've read after having surgery it is recommend you don't exercise for 6 months to 2 years, couldn't handle that).
I quite often feel it limiting my breathing, if I inhale deeply I can feel my lungs pushing against my ribcage before filling as much as it feels like they should. Getting punched dead in the middle of the chest literally knocks the breath out of me, anywhere but dead centre doesn't have the same effect.
Used to know someone who had it slightly worse than me, still not as bad as the photos here, but he had been a boxer. He was told by his doctor to quit boxing as a hard punch to the chest would likely kill him, putting a rib straight into his lungs.