Thinking about my research, I am so depressed now. My boss and I sent a paper to a journal last year, and it was rejected. This term, I finished a term paper, and the variable I am interested in is not statistically significant. My friend who is in the same program got a paper accepted in a conference with her adviser. She told me that she didn't do much but the professor is just so nice to add her as a second author. This semester, she had hard time finding a topic and I shared some of my thoughts with her. It turned out that she is also getting nice result.
Why don't I get any luck or did I miss sth? I lose confidence doing research.