I'm not sure if it's the same experience you have, but when I absolutely cannot make myself do anything, fighting it will make me angry or feel worse so I just allow myself to rest and try again the next day. Sometimes that means just watching videos all day and nothing else. If you can't even do that, daydreaming about something that makes you happy or feel comfortable or meditating may be an option. Sometimes it just takes one thing, a comforting thought or a favorite show/film to get you going again.

Okay so I used to deal with this but I'm pretty sure it's mainly from my ADHD bc stimulants helped with it. If it's the same issue, though, it's called "executive dysfunction" and iirc, C-PTSD can mess woth executive functioning. Basically it's an issue with ur neurotransmitters that make it so the motivation systems in your brain don't exactly work. So you'll know what you want or need to do but you might as well be paralyzed by your own brain. There are tips for it, though, even if it means watching ADHD youtubers. But see if any of those tricks help! Good luck!