Two faces of feelings talk: expression and commitment
Talking about your feelings aims at at least two different and sometimes conflicting ideals: the expressive and the committive.
The expressive ideal is based around the structuring premise that your feelings exist independently from their expression. The job of expressing your feelings is to make explicit the already existing feeling states. The central virtue of this ideal is sincerity: producing an expression that is true to the underlying feeling (also: articulateness, openness, etc.).
The committive ideal is based around the structuring premise that to express a feeling is to take a stand. The job of expressing your feelings is to create a reliable system of affective expectation that others (and yourself) can use to coordinate their activities (and feelings). The central virtue of this ideal is honesty: producing an expression that can be prospectively relied upon.
The two ideals can come into tension when someone has uncertainty about their own feelings. If a person is not sure how they feel, then the expressive ideal calls for expressing that uncertainty. But expressing uncertainty is contrary to the committive ideal, because it is not conducive to prospective coordination. Your uncertainty clouds your likely affective responses; being uncertain is almost as good as hiding how you really feel. The committive ideal calls instead for resolving the uncertainty before expressing the feeling.