Q: Please give me some tips for dealing with negative comments.
A: First, each brain is unique. Therefore, each person's opinion comes out of that brain and may have little if any relevance to your brain's reality.
The saying your opinion is none of my business doesn't imply a lack of caring. Rather a taking care that another brain's negativity impacts my brain as little as possible.
You do choose how you will respond to criticism, especially unsolicited criticism. A quote by Viktor Frankl speaks to this:
Everything can be taken from us but one thing—the last of the human freedoms—to choose one's attitude in any given circumstance.
Second, recognize that criticism is often a defense mechanism used by individuals who struggle with self-esteem issues. After all, if they would never do what you did (assumption being they disagree with what you said or did), then they must be better than you are or at least do things more perfectly. This perception gives them a temporary, though specious, boost to their self-worth. It's a dysfunctional strategy, however. In order to maintain their tenuous grasp on self-worth, they must continually find fault with others.
When you receive unsolicited negative comments, try scanning them mentally to ascertain if there is anything you can glean from them. If so, good. If not, metaphorically blow the comment away, much as you would blow a rose pedal from your outstretched palm. This is one example of implementing the 20:80 Rule: 20% of the negative effect to your brain and body is due to the event; 80% is due to your response to the event and the weight you give it.