I agree with rezzeJ in the sense that artistic expression is not always synonymous with emotional expression. Sometimes "art" or creative self-expression is problem-solving or protesting or exploring or science or math or theory.
But there are ways of committing emotional suicide. A few that come to mind include
1) Expressing your feelings and having another person tell you not to feel that way, or worse, saying "You don't feel that way." You then decide never to express your feelings again.
2. Surrounding yourself with people who don't care about your feelings on a regular basis.
3. Surrounding yourself with people who expect you to listen to their feelings but won't accept or consider yours.
Feelings need to be faced and questioned, interrogated even. Surface feelings hide other feelings that lie deep within a broken self.
But the advice to "get off the couch and start painting again" - yes, sure, if painting or writing or music-making is what you should be doing. But we do that thing for many reasons, not just to express emotions.
and of course, I might be wrong altogether.