I know exactly how you feel....
I used to have a boyfriend who was preferring family to me ...and then a friend to me....And i did feel extremely anxious, hurt ...just the way you say you are feeling. Could not concentrate... nothing. total wreck until i decided to end it.
Usually, these feelings and these kinds of unstable relationships - or relationships SEEM unstable - is a sign of a borderline personality disorder.
Try this, i found it really good:
http://www.4degreez.com/misc/persona...sorder_test.mv
I wouldn`t say that this is ABSOLUTELY a sign that he prefers his family to you all the time! It happened just once!
Unreasonable or selfish is not what i would call you...i would call you anxious and afraid....and i understand your feelings