Aren't you overcompensating for something?

I can't stop my mind from coming up with new ideas. Constantly, be it during work or while trying to sleep, I have to stop what I'm doing and note down the new ideas that came to me out of nowhere. Restless creativity. Never-ending tension for not creating more. The feeling of 'I could be writing right now' follows me at all times. So why is it that I can't write?