I'm so sorry you're having a hard time! I've definitely gone through that, many times. I've had writer's block needing to get stuff done for work all the way to lying in bed and being so depressed that I had to talk myself into getting up to go to the bathroom for an hour, because that was just too hard and too overwhelming for me.
Here's some of the things that I do... make really detailed lists. Like
- Sit on couch.
- Open laptop.
- Open document.
- Read over what you have.
- Type one paragraph.
- Drink some water.
I know it sounds ridiculous, but there's something really good about checking off lists. But when you're having a lot of trouble, the things to do have to be so tiny that you can handle them. I also promise myself some reward... "Okay, get that one paragraph done and drink some water, and then you can take a break and watch 30 minutes of TV in bed."
The thing is, it takes some of the pressure off, and then sometimes it's easy enough to just continue, finish and then watch TV (or whatever). Sometimes just getting that paragraph done is a victory, and I watch TV like a zombie for 30 minutes, then I try again. And this is just an example... works for anything. It's not easy though. You have to fight and fight and fight and sometimes it doesn't work anyways. But give it a try.
I can certainly relate (I remember spending weeks working from home and just sitting on the couch starting at my laptop, for literally weeks, doing nothing, not because I was lazy, but because I was just blah-blank-unable to function-unable to think). I'm rooting for you! Good luck!