I’m Australian, and am on daily opioids (The drug is called Targin) for chronic end stage kidney failure/Cystic fibrosis. If I travel to America, will I be charged with possession of narcotics even with my doctors letter?

I am wanting to do a possible one week trip while I still have some health, maybe to New York/Salem.

I know that the USA is super strict with narcotics due to the purdue scandal,
Yet if I have my doctors letter, all original packaging of my medication etc, will I be ok?
I just don't want to end up being charged with drug possession of my legally prescribed medication that makes me have a bearable quality of life.

Thank you 😊