how to support my honey who is struggling with depression?

I'm just looking for the best ways to be a support to my sweet man. He and I got into a crazy fight the ended with him confessing to me that he is struggling with depression. This isn't new of course but this is the first time he has dipped since we became adults so I'm seeing it from a new perspective. When we were in high school I would take I personally and feel I was causing it. I know that's not the case now, and I want to know if you have any advice on how can I be there for him while he is struggling. Thank you!!