I'm sorry you have to deal with this (again). I periodically fall back into old habits that my depression forced on me, but it has gotten better with the years. I've been living on and off with knowing about it for a good ten years now, after all, whereas I'm pretty sure it all started when I still was a child. So it's a chronic thing that sparks from time to time when situational stressors are added to my life.
That means I often struggle for weeks or months to write anything. So I know this feeling of hopelessness (add unrest to it because not writing just irritates me). I sadly can't offer you any great tactics, but I wrote a piece on my (half-dormant) tumblr dubbed "Writing with Depression" back in July – maybe you can take away a thing or two from my path? I tried to offer ways to deal further down the post, as well.
Anyway, maybe it helps you somehow:
I can only say: be kind to yourself! I know it feels wrong not to write when it's something that helps you keep your mind together, but stressing over it just adds to the blockade that's keeping you from writing already.