Staying On Top Of Work

I m currently completely f**king stressed out over my work. On Sat I didn t sleep, and I worked all day and all-night (much of it needless and unproductive) on Sunday I am so stressed out that I can t concentrate. How do you stay on top of work? Or do you have the same thing? Btw, I m a freelancer
https://www.myptsd.com/c/threads/staying-on-top-of-work.50458/