You aren't ever going to run out of things to do. Literally - there will never come a time when everything you could do is done. Some tasks are projects that have a beginning and end, others don't, they are ongoing work. But in any case there is always more you could do, more than you will be able to do.
Write a list, if you are afraid you will forget. I put reminders in my phone too. Prioritize your list, do the more urgent or important things.
With migraine, yes I would get hallucinations with the ones that dragged on. Like dreams they were, mostly fantasies about how to stop the pain by walking in the right direction or solving some math problem.
I do often hear music in the fan sound or running water. Those are funny because it sounds like music coming into my ears from outside, but is coming from my mind. Not particularly good music.