I even offered to pay for the whole thing,
Hah. As did I, to no avail. In the wake of the break-up, in one of the few torturous post-parting sobbing, pleading conversations over the phone, she told me that no matter what, dating me was the best thing that happened because she was going to see a doctor, and even if I didn't get back together with her, she was going to see one anyway, and she was finally committed to taking care of herself.
Months later I ran into her on the street. Typical awkward ex meeting. I asked her how she was and did she see that doctor. I think you already know what the answer to that question was.
I walked away relieved, because it absolutely validated my choice. Even at her darkest, lowest point, I had zero ability to affect whether or not she sought help. Even the destruction of our relationship wasn't enough, and the most she would do is offer lip service. Though I was relieved, I took no pleasure in her predicament. It saddened me greatly, and to this day I find myself really hoping that she's out there somewhere doin alright. I'll not be there to find out though. Ever. And I'm totally cool with that.