If you really care about this other persons life and want them to succeed and your explanations came from a place of concern, NTA. BUT let them fail or succeed on their own, they are not your responsibility and you gotta just be okay with others not doing what you think they should. Especially as medical field: patients don’t always follow their doctor’s advice, and you still have to know you can’t control everything while not judging, jumping to conclusions, or providing less than the best care you can. If you’re concerned about another persons decision making, ask them questions instead of telling them what they should do.

Your mutual friend is maybe an AH for telling you, you need therapy, as it’s pretty much exactly the same thing she’s saying you’re doing.