What sort of things do you need to revise for ? Is it memorising things? What sort of task do you need to do? Because that is in fact all, just doing it. What helps with me is working for 45 min, and then giving myself a 15 min internet break, both to be timed with my kitchen timer, so I don’t run over time. That way studying stays doable. Try it. I find working with a kitchen timer and prearranged timeslots way easier than sitting around and waiting for destine inspiration to hit me so I can work. Good luck !