It sounds like to me if she doesn't go into therapy, she WILL end up having some sort of breakdown eventually. You can't have that much crap going on in your past to not deal with it. You were probably the best thing that ever happened to her, and she's blowing it. However much you love her, she sounds like she's in that wishy-washy mode where she needs to get her own shit sorted about before she can really love anyone else.
Besides, she's a fool for giving up such a good guy.
“Inside every cynical person, there is a disappointed idealist”--George Carlin