I went through a similar time a few years back. Here’s the exact thing I did to overcome it. If you persist with this for a week or two, you’ll crack it and it’s as simple as it gets.
What you need. A notepad, a pen and a way to get fresh air or exercise that you’ll enjoy, preferably while listening to your favourite music as you do it.
Whilst you work, and you think of tasks that need done, make a list for the next day. Leave the notepad right next to, or on top of your mouse mat, so it’s the first thing you see. (don’t muck about with reminder “apps” .. I tried. Just stick to plain old pen and paper used by humans for hundreds of years). If you think of more tasks later in the day, go to your list and add them.
Wake up reasonably early. Pull yourself together after breakfast/coffee and start working your way through your task list. As you complete each task, strike a big fat line through it.
You are not allowed to do ANYTHING else until you’ve finished your list. No skype, socials. Nada. Switch them off. The list is EVERYTHING.
If there’s a task that can’t be done, add it as first item on tomorrow’s list with a star next to it. Starred tasks cannot be ignored any longer and take priority on that day. If it carries over to a 3rd day you’ve failed. (unless it’s an ongoing task that needs more work).
As you’re working through your list today, and you think of more things to do, add them into tomorrow’s list. Don’t take new tasks today. Your priority today is today’s list. Not tomorrow’s.
It’s a great feeling seeing all those tasks that were hanging over you weighing you down, crossed off your list

believe me.
Your list today is complete. Switch off your PC. It’s now time for your exercise before anything else. (even eating).
Me, I go on my bike for at least half an hour (or more) while listening to my favourite playlists. Or I walk the dog. Do whatever you’ll enjoy. You can do some quality “thinking” while listening to music and taking exercise. It gets procrastination out of your system.
Oh. You can eat now if you want
So, your tasks are done, you’ve cleared your head, you’ve had exercise. Do you still feel the need to chat online?
You might at first. But I bet, after a few days you won’t. You’ll be energised and probably want to do more and more work.