Howie, you are already helping your girlfriend by 'giving a damn' and asking for help yourself. Good on you.
Emotional pain is such a personal thing and as long as you do not 'smother her' and keep open lines of communication so she is aware that you are ready, willing and able to listen and talk to her when she is ready.
I agree with the other Hubbers, at some stage she will need professional help as long-term emotional psychological pain can manifest as a form of referred pain which then becomes actual physical pain which will make things altogether worse.
In the meantime, ask her if she would like to try writing down what it is that she feels and why she is in pain. Nobody else needs to read her words and it can always be ripped up or disposed of when she has done it.
This helped me in my time of need - it is a progressive healing process that won't happen overnight.
There are a myriad of things that she could try such as Reiki, Energy Healing, Art Therapy, Music Therapy, etc but the most important advice that I give you drawn from my own personal experience is to keep doing what you are already doing ... give her space, give her your love and support but most of all realise that her healing will be progressive and it will take both time and energy to regain her wellbeing.
I wish you both well ... you will be in my thoughts.