It’s not just that your girlfriend doesn’t want to talk about her feelings, you have to understand that much of the time she probably doesn’t feel much of anything or she feels things too strongly to be able to articulate it. I understand how much it hurts to see someone you love suffer in an intangible way; you want to be able to do some thing or say something to make it better, or perhaps you want to force her to do something or say something to make it better but there is nothing for anyone to do or say.
Of course your feelings matter just as much as hers, just as your emotional well-being matters just as much as hers, that being said I urge you not to put any blame on her for how frustrated this is making you. There’s nothing she can do and if she feels that her depression is becoming a burden it will make things exponentially worse.
You need to talk to other people that you trust about your feelings. You need to listen to people who’ve gone through depression so you can better understand your girlfriend. You need to listen to people who’ve gone through loving depressed people so you can learn from their mistakes and victories.
My best suggestion on how to communicate with your girlfriend is to start talking about nothing at all. Talk about inane things to fill the silence or to drown out the noise. Talk whenever she doesn’t ask for quiet. You’ll be surprised at the random occurrences of genuine feeling she might have once you’ve created a safe environment of insignificant chatter.
Also, keep this number around: 1-800-273-8255 (1-800-273-TALK) It’s the national suicide prevention hotline.