Checking back I think the Internet ate my last post to you, so I'll try again. If you get two in a row that say much the same thing you'll know why.
First off I'm glad talking here is helping, trying to work it all out for yourself in isolation does not really work, just makes you more stressed.
It's not really necessary for you to understand what is going through your GF's head, it's sufficient you know she is ill, her thoughts are not as they should be, and that you care.
There is no hard and fast rule on contact, and I think texting is a good way to try. it can easily be ignored if it is too much at the time, can be gone back to if needed, and allows plenty of time to make a response - if that is possible.
You may not get much back to start with, which is hard. What you talk about? Well in my case happy things past and now, hope for the future and generally things away from the ward would have been a help.
My partner told me about movies she saw.
We are all different. I did not handle being asked how I was , at least not too often, very well as it reminded me of the mess I was in, plus often I did not know the answer - more pressure. Again your GF may be different and want to talk when the time is right. I guess you ask when your instinct says to.
There is always a feeling of worry in contacting a person's family, however things are different if they are in danger than they are in normal life. As far as I know most people understand later on and many are even grateful as it is a battle they no longer have to face.
You said you have no support, can I suggest, like Baet123, you look after yourrself? One good way is counseling for you.
We hope to hear how you are going