<human>: Condense the text into a few key points

/r/askwomen suggested I post here so here it goes:

My best friend "A" (26/f) just found out on Sunday that her boyfriend "J" (35/m) of 8 months has had another girlfriend "C" (26/f) for the last SEVEN (7!!!!!!!) years.

J has been telling A that when he moves back into town in a few months, he'll be ready to settle down. Apparently he had been telling C the same story. Well, A found out about C, both cannot believe that they got played, and I'm trying to be the best support system possible for A.

Have any of you had to be that support system before? My friend is completely crushed right now and I want to help her to move past douchebag J and move on with her life. I realize that she isn't in as bad of a place as C because her relationship was only 8 months (unlike C's relationship of 7 years). She's a complete sweetheart and all she has ever wanted in life is to settle down and have a family. Her luck has been pretty piss poor to date.
<bot>: My best friend is coming out of a really serious relationship and is in complete shock about how it ended, how can I best support her and get her through this?