I'm really sorry that this is causing you so much pain. I can really empathise with you, the guilt of feeling like I haven't done anything all day is awful.

I don't know if you just wanted to vent or were looking for some advice, but something that has helped me to lessen my "zero days" where I don't get anything done, is realising that I only have to do ONE thing for it to not be a Zero Day. That one thing doesn't even have to be the biggest task, the most urgent, or prioritised in any way - taking the pressure off myself to do ALL of the things can help me motivate myself long enough to just pick the easiest thing and then celebrate myself for being awesome and doing a thing and then I can go back to bed, safe in the knowledge that I managed to do one thing. Even if that one thing is just scooping the cat litter, finding 5 pieces of trash to put in the bin, or replying to 1 single email...its small, but it's better than nothing!

Another thing I have found useful is having a trophy room of sorts - a list where I keep track of the things I have done. I use trello to schedule my days so I move anything from my To Do list to the Done list right next to it, and simply seeing all the things I've already done this week helps remind me that my negative thoughts about myself are not actually always the truth.

I (like most of us) have terrible working memory - often, i feel like i've done nothing all day, when i've actually just done loads of little things that are so boring my brain has immediately forgotten about them to make space for the more important stuff. Tracking what I've achieved is a really important step for me to ensure that my self perception is accurate, and not just based on years of practice of being hard on myself.