So you're already working on it. She's already seeing people about it and is apparently willing to subject herself to diagnosis and whatever might come of that. I'm not sure what more you're hoping for here? You're already taking all the necessary steps.

If she can not overcome her issues (which, again, she's apparently already working on so I'm not sure what more you want anyone here to tell you), your relationship will become unsustainable. Meaning your relationship would end. Should end.

Just because she's received a diagnosis it doesn't mean that it's the root of our problem. The situation could very well be that the issues in our relationship are completely separate from the diagnosis that she's receiving. I'm asking for advice in case someone has a suggestion or idea in addition to what's already being done.

Yeah, that's threatening. Something doesn't have to be phrased as a threat to be one.

The definition of a threat is making a statement with the intent of inflicting damage or a hostile action done with the intent of seeking revenge. Sitting down with your partner to try to get them to see the likely negative outcome of a problem unless it's resolved is not the same as threatening someone.

And again, if you ever get to the point where "you can not be a good boyfriend anymore" you should no longer be her boyfriend.

I don't think that just because an issue has gotten so big that the romance is starting to dissipate, the relationship should be abandoned. I believe that it's worth trying to resolve the issue before giving up.

The fact that you're making it about your own behavior as opposed to the health of your relationship is strange to me.

How am I making it about my own behavior? I'm literally asking how to save the relationship given the factors on both her end and mine.