As for the topic, if possible I'd be grateful for general answer and more specific one regarding following situation:
My girlfriend has a clinically diagnosed depression (she attends visits with psychiatrist and is taking medications). Because of that she often has very bad mood (nowadays it's less common thankfully). I am always trying to figure out some ways to help her, generally when we are spending time together she feels alright. But except for her free time with me she is studying hard to get her college degree and has a part-time job which are both very stressful for her.
Sometimes when she is in a bad mood she tells me she wishes I were next to her (we live in different cities and usually see each other on the weekends only), and that she feels terrible when she is alone - when I hear it over and over again makes me feel as if I were entirely responsible for her happiness. Obviously I know that her depression has a huge impact here and I care about her a lot and want her to be happy, but I want her to be happy not only when I am with her but also when she is alone, so once when we were hanging out I suggested her to find some hobby. I thought if she had some passion like art or whatever else, maybe she could forget about her bad mood for a while. I told her something between the lines:
Me: You are only attending classes, working, and when you're back home you're studying. Have you thought about finding some hobby?
Because of my poor word choice she took it as if I were telling her that she is boring. I immediately corrected myself and explained what I meant and she said it's ok and that she understands what I meant.
Fast forward few weeks, she was in a very bad mood again and said:
Her: I know you think I am boring and that I don't have any hobby
Obviously despite her telling me it was fine she took it to herself and I felt very bad about that because that was totally not what I wanted her to think.
Is there something I could do to fix that? I don't think that talking would work, but maybe I'm wrong. From time to time I'm trying to do some new stuff with her hoping she will like it (programming, learning foreign language), but even if she enjoys it in a moment it's nothing she would like to do regularly. Can I somehow encourage her to try out new things on her own / look for some activity she enjoys doing regularly? (I'm aware that in case of depression that's not an ultimate solution if any at all)
And in more general case, how could I tell that to anybody (to find a hobby), without implying that they are boring?