Starflower - you could try to use a hiit timer/app that is developed for sports training? I have a simple app on my phone that you can set your own timings to work(out) and to rest?

I've been really suffering with lack of motivation over the past couple of months. I've had mixed feedback from my supervisors had meant that I've gradually lost faith in my ability to write and even research even though it looks better now than it did a few months ago. I now just feel very tired and my brain feels fuzzy and anxious a lot of the time. It feels like I'm very behind and there us so much more to do...