You aren’t. Again, her emotions belong to her. There is nothing you are doing to intentionally cause her distress. It is the consequence of circumstance.
What would be adding to her turmoil is offing yourself. Then it would be your choosing. I know that’s not what you, or anyone, wants.
You’re reaching a point where you realize you can’t do anything about your situation to make it better. The only thing left to do is let go. The problems are going to exist regardless of what you do, otherwise they’d be fixed by now. You don’t know that that’s okay yet.
I can tell you feel deserving of the guilt. You don’t. You’re torturing yourself, because maybe you believe she will benefit from it, but that hasn’t happened. Your guilt is only exacerbating the problem.
I know you want her to be happy, but that isn’t up to you. No matter what you do for people, they will react to it independently. You need to stop holding yourself accountable for her unhappiness. If she cannot see that you are sincerely trying for her, that is her problem.
The only feelings you should be concerned with right now are your own. You are broken, and no one will know better than you at how to fix it. You are allowing your emotions to carry you, instead of scrutinizing them, and finding out why they exist.
The more you watch yourself, and how you react, the more control you have. You have to start questioning your emotions, instead of letting them take you away.
I used to be in a very similar place emotionally. I’m past it now, and this is how I got there. Take responsibility for yourself, but more importantly, recognize when you are taking on the emotional responsibility of others, and let it go.