Well, I had to get on TRT (testosterone therapy) at the age of 31. This is due to cycling when I was 20. So yes... you will damage your body.
And I understand. Everyone around you is a beast. Most people I knew when I was 20 are all fat slobs now. Just maintain a healthy lifestyle. Your friends are probably around your age and I can tell you that most 19 year olds do not research and will end up with scar tissue, flabby skin and a whole bunch of internal issues. You will be the one 10 years from now that they wish to be.
Stay classy, San Diego.