Wow Iam sorry you are going thru such bad times, BUT I think he is not very nice to just end a friendship with you over a girl he barley knows, It sounds like you love Don and want to be with him ( correct ) He will find out in his own time just what a snot she really is, and then he will do what most guys do, want to come back to you, Thats where you need to stay STRONG and remind him that he had his chance and choose her, good luck to you
I hope you meet the man of your dreams and put this behind you
