A good suggestion made to me was to find another therapist while you're still seeing this one. That way you can build up trust in someone else and you will have someone else to turn to.

Can you say more about how you're in so deep?

I realise you care for her, but can you see that as a client a) she shouldn't have put you in this situation in the first place, and b) you aren't responsible for her well-being. Does it look to you as if she has no other means of support? This is irrelevant other than the fact that it makes it feel harder for you to break away.