You sound like an amazing person and such a supporting partner, that's such a beautiful thing to see.
Personally when I have bouts of anxiety I really like being held by my partner, just like one huge prolonged hug, he doesn't even have to say anything sometimes, just that physical contact makes me feel safe, warm and loved, which tends to calm me down heaps.
When I have worse attacks it usually requires my partner to be a bit more vocal in telling me that I'm okay, I'm safe and thinks like that. I also like to hug teddies (but that might just be a me thing).
Also communication is really important. When she is feeling better ask her what she would like from you when she's having bad bouts of depression and/or anxiety, so when it does come, it'll be easier.
Also please look after yourself as well, I don't know what it's like looking from your side but that's what i try and tell my boyfriend too.
Sending hugs to the both of you!