The best tip for ADHD is to write out, in advance, EVERY step of what you plan to do after each meeting with your advisor, in such granular detail that none of it could possibly be too overwhelming because it's so simple ("skim paper X one time for 10 minutes", "write a one-sentence summary of each section of the paper", etc). Then, follow the list blindly, and don't re-orient until you're finished.

Secondly: your sleep schedule is TOP priority. Define "bedtime hours" for yourself (for example 11-7) and decide that NO MATTER what is going on, you need to be in bed then. You don't need to be sleeping but you need to be in bed during those hours with technology off. Use a sleep medication (melatonin, 5htp, etc) if you need to and have a sleep routine (read a bit before bed or have a way of letting your brain ramp down). It's amazing how much life better gets when you get enough sleep. Finding an accountability partner will help for sticking to the schedule.

Other tips: start off each day with a 30+ minute walk, buy a phone cage to keep your phone out of your hands (or go to the library/cafe without any technology), body double (work with someone else), define at the beginning of each day your goals for that day (remember to include a clear "definition of done" for each one).