[miitty]

Many good tips answered already like chunking tasks. But like a few people have mentioned the might be a deeper problem.

There might be some pent up trauma in your mind (could just be something totally mundane like not feeling heard when you were 5 years old, or could be something more serious). Somehow that trauma may be associated in the mind with the idea of things you 'have to do' or whatever, and the procrastination is a subconscious defence against having those feelings bubbling to the surface.

Do an experiment: can you close your eyes and find something in your mind to think about that makes you feel negative emotion? Try find something, maybe cry or just let yourself feel those feelings for say 20 mins. Having done that, do you feel more able to complete or organise your tasks? If so, something like what I'm talking about might be going on.

The road to really getting there might be long, but just realising this connection can be a big help and lead to more and more improvement as long as long as you can keep not shying away from those negative emotions.

[miitty]

But also, don't get into a self-negative interpretation of these thoughts or experiences. Letting yourself be upset is good, but also self-sooth and be forgiving on yourself. It won't work if you just blame yourself and tell yourself you're bad/stupid etc.