Welcome! There are many people here who share you story... .
I want to spend my life with her but until she starts actually going to dbt classes and taking it seriously it's very difficult for us to have a conversation because I don't want to throw her into another rage again because her stability is so fragile lately. I just need advice on what I can do until she begins to use the skills she's going to learn in her therapy and classes.
I need to give you the bad news first: Even after she goes to therapy, things will probably not change. Therapy
may help reduce the number and strength of rages, but they will always be there. DO NOT rely on hope of her "getting better".
But the good news: life can get better when YOU skill yourself up. There are a number of essential skills that you can learn to help you talk with her, help the relationship become easier, and to make you feel in control again. These do not "fix" your relationship, they just make it bearable.
I recommend reading about Validation first. This is a way to talk with her so that she feels heard. At the moment she is raging because she doesn't feel you understand her. The problem is you are listening and talking like a man. Validation teaches you to ignore her words (!) and focus on what she feels instead - with trying to solve or understand. It sounds crazy - but it works.
If you are ready to learn, start reading here:
https://bpdfamily.com/message_board/index.php?board=36.0Then post some conversations and we can help guide you.