According to Shouse: http://journal.media-culture.org.au/0512/03-shouse.php/Shouse (2005):
Feelings are personal, emotions are social and affect is prepersonal. In other words, feelings are how we understand and label our sensations, based on our own experiences. Emotions are how we project these socially (through facial expressions etc.) Emotions can therefore be manipulated to fit with social norms. Affect is more abstract and is the 'non-conscious experience of intensity' felt through the body, before we name and categorise it.
Reference
Shouse. Feeling, Emotion, Affect. M/C Journal 8.6 (2005)