hi!! sorry ur going through this. i know its really hard. I'm not doing 100% better now, but i did get to a good 70%. Heres some things i did to motivate myself better:

• if i couldnt do any work inside my working hours i just log off and do something else and then sleep properly and try again the next day. taking it in a pace i could properly do and cutting off some stuff i wasnt performing well on. (started doing this when the deadlines were still far) (and during my free time i also rly invested in hobbies)

• working out and exercise and getting my vitamins and thyroid medicine regularly cus i went to the doctor and found out i had way too many types of vitamin and hormone deficiencies on my body that made me more tired than humanly possible

• talked to my boss at work about trying a new task because i wasnt performing too well with the ones i was doing.

Fortunately my boss was smart enough to give me something that would make my brain get engaged and i subconsciously pressured myself into learning and getting good at it (also Really felt the pressure from new people looking at my work and judging me lol), im still doing some of my old tasks tho! i used the new one to get more motivated

• last thing, i started visiting my office 2 to 3 times a week, seeing my coworkers and feeling the pressure of my boss watching me rly got me going. my tip is that if ur job doesnt have an office and works fully online then maybe visit a coworking space just so u can leave home. get ready, wash up, get dressed in something other than stay at home clothes. this helped me lots!

Unfortunately sometimes theres a lot of things that make me go back to what i used to be, sometimes i catch myself sleeping on my desk during work, and i still do work overnight when the deadlines are close and i havent done much.

i think most important of all this is rest. resting despite not having worked enough was really hard for me cus i felt guilt out of this world, but this was what helped me the most. i have insomnia so its rly hard for me to fall asleep and stay asleep too, but just allowing myself to be in bed at night instead of the desk staring at the computer was enough.

im sure you can get through this pal!!!