Hi I live with severe depression but also support my husband who has bipolar disorder, though it is well controlled, so I have experience from both sides of the fence.
I feel very guilty that I worry I'm dragging him down and not meeting his needs. Sometimes that makes me want to withdraw even more. The best thing about my husband is that he doesn't try to fix me and still loves me. The hardest thing is that he is not good at showing his care or encouraging me to talk when I feel withdrawn. I interpret that as that he's not interested or can't cope with how I am so then I withdraw to try to protect him and keep things to myself.
I try to challenge my negative thoughts and make myself think of at least a tiny positive thing. When my husband is feeling low and negative he doesn't appear to do that, will often take to his bed or just curl up,and I feel frustrated thinking why doesn't he try as hard as I do, or at least a bit. I can get quite short with him. Trouble is, I don't know how hard he has tried, not really, I'm not in his head. And trying to fix him rather than gentle encouragement never works. Hmmm, difficult issue. My care coordinator once said 'it (mental illness) is hard to live with but it's even harder to live it. Kudos that you are still there for her, that's so valuable, best wishes as you try to find a way through.