Most Helpful Guy
I'm not a psychologist, but as far as I know depression is caused by one or both of two things:
1) Lack of certain chemicals in the body. See a specialist for that.
2) Lack of meaning in life. If this is the case, join the search.
Depression caused by lack of meaning is a growing global epidemic. But once you start actively searching for it, you are part of the sollution. You won't get better immediately. You might even feel worse at times, but you will be alive as long as you keep searching. And one day, you might find it.
Most Helpful Girl
I hope this works out. Usually its hard when both people in a relationship have a mental illness. My best friend has bipolar depression and her boyfriend has anxiety and whenever it gets too much she comes to talk to me. It can work. Stay strong. I'm also dealing with my own mental health problems so I can understand to some extent what you're going through. I wish the best for you in your relationship :)