Yes, there are things you can do. But it's a slow process and will take patience. There's lots of people on this forum who are wiser than me but here's some ideas:
1. Look after yourself. I know this sounds strange, but it's really important to look after yourself when your partner has depression. It's important not to get dragged down, or to lose a sense of yourself. Make a list of supportive people and activities that you enjoy, and deliberately get out and do them. Keep your own positive joy in the world, and your perspective. It will help you help her.
2. Try to get some support for yourself around depression. It can be really helpful to understand the issue better, and talk to others. There are a couple of carers organisations though I'm not sure if they still have support groups. This forum has a carers section, and there is a thread called "being there for someone who pushes you away" that has good ideas.
3. See if you can gently encourage her to get some help:
- Provide her with a list of emergency and online support (there's a good list on this website). She may seem to ignore it, but you never know if she might call someone when you are not around. Print it out, she won't have the energy to look it up.
- If she is willing to go to the GP, help her get there. GPs are the gateway to treatment for depression and can provide referrals etc. Some are better/more experienced than others, so it might help to ring and check them out, or meet with them yourself first.
Sometimes someone who is depressed or anxious pushes others away because they fear they will just harm the other person and spread the pain (that's another reason it's good to look after yourself). Sometimes it's because they feel they are no good, and are testing this theory by seeing if you walk away. It's really hard to know, but it's worth asking her.
Assuming you want to stay in the relationship, my guess would be - don't back off further. Stay connected, but safe/healthy, give her a little space but be a consistent supportive presence.
I hope that is a little useful - I'm a bit tired so apologies in advance. I am making suggestions without knowing much about you, so this may not suit your situation.
Just wanted you to know that we understand how hard it is, and the anxiety that you are going through.