They won't do anything after you've sent a selfie anyway. Same thing happened to me. They'll ignore all of your contact attempts. IG support is pretty much non-existent.
My first offence occurred when I was 13 years old. I'd chalk it up to inexperience and a lack of ability to anticipate the consequences of my actions. I was really self-absorbed. I'm not the same person I was back then. It has almost been a decade.