hmmm...
All I can say is pray about it.
I mean if you love her for real you wont break up with her just cuz of distance. But if you are really considering breaking up with her, maybe you didnt really love her. but thats just my opinion.
as for your ex I dont think its a good thing for guys and girls to live together without being married, because there would be too much temptation. not to mention the the feelings of the past.
but these are just my thoughts and opinions.