No it has not done any damage, do not worry. Just don't touch Xanax again and you'll be fine.
edit: I just realized you also posted another thread about this same issue not too long ago. If drugs are causing you this much anxiety stop doing them, or at least research them thoroughly before you do them so you aren't in the dark about the possible consequences of using drugs.
You have not done any permanent damage to yourself but drugs are not a good thing for the body especially at your age. The more you use drugs the higher your chance of getting addicted becomes and the greater the chance they will effect your body in a negative way.
