The noble and polite character of Rasulullah (Sallallahu Alayhi Wasallam)

Q: I read somewhere that the Holy Prophet sallallahu alaihi wasallam at some occasions used harsh words to people. It was written that he would impugn then. Is the definition of impugn which is meant in the ahadith ‘to cause people to doubt someone's character, qualities, or reputation by criticizing them’. Also when we say harsh words, what was the manner of the Holy Prophet sallallahu alaihi wasallam in that case? Did he say the words in an angry tone?

Being proud of one's achievements

Q: Allah Almighty has blessed me and I have become a doctor. I am so happy and I have worked so hard for it and Allah has blessed me, so I would like to tell everyone that I have become a doctor and be proud about it and receive congratulations. Should I be humble and not tell anyone or there is no wrong in doing what I am doing? I dont want my Allah to be sad with me.