I agree with the “don’t make saving her your life mission” bandwagon. You can’t save another person. You can be a good friend, you can be a good listener, and you can point them to helpful resources. But you can’t rescue people.
On that note, people with this many unresolved problems usually need friends more than they need lovers. Romantic relationships in these situations are usually not really going to be anything but emotionally exhausting to both parties. Don’t get so wrapped up in her drama that you don’t get your own needs fulfilled, and don’t forget about the opportunities you may be missing with an emotionally healthy and available partner.