I spent my first year consumed with imposter syndrome and struggled to reach deadlines. I felt I got no headspace from my phd and either worked through weekends/holidays or did nothing. It took me ages to create a system that meant I got enough done to make progress without the feeling of constant stress.
Here are a few tips that helped me.
Every Friday I work out a plan for the following week.
Motivation- forget about it. You might go through periods of feeling inspiration and times when you can’t be bother or stuck. Waiting for motivation will get you nowhere. You need to get past this and see the phd as something you do everyday (I stick to mon-Friday). See it like a job, or brushing your teeth, or doing laundry, no motivation required just do it. If you can’t focus to read or write then do something else. Doing anything productive will make you feel so much better. Fix your references, learn how to format your thesis, look for workshops/seminars/conferences etc
Learn to love criticism. It’s hard to not take it personally, but it could be worse, you could have a supervisor who doesn’t bother with feedback. Constant criticism doesn’t mean you are failing, it’s part of the process so that when you submit your thesis it is the best it can be and you can get through the Viva. Accept the criticism or justify why you disagree, either way your work will benefit.
If you don’t already, follow Tara Brabazon on you tube, she is a fountain of knowledge.