Something I personally do, if possible, is have some sort of fidget toy next to me when I feel fidgety/anxious. It is good to stop and play with something to relax sometimes while you do work to prevent yourself from getting so overwhelmed that you procrastinate or panic. Limit other distractions, though, such as your phone. Maybe put it far away from you so you’re not as tempted to reach for it and scroll through media. You’ll probably only grab it when you need it. But don’t stop yourself from taking a small break if it’s really needed. Another thing too is to write all of your work down in a calendar planner, so if you’re not sure what’s due when, you can look at it and plan accordingly. I know this is hard with ADHD, but try your absolute best to plan out when you do your work. Set an alarm so you don’t forget, which I know is an issue, at least for me.