Leave something easy or fun unfinished in the evening that you can start with in the morning. Fear of failure can make work hard. The prospect of discovering that your last several months of work have been for naught may be what's stopping you. Read Alan Lakien's book How to Get Control of Your Time and Your Life , which is recommended even by people who hate self-help books. It has invaluable techniques for getting yourself into productive action.
Most people find that their personal life and their ability to do research interact.
For some, work is a refuge when everything else is going to hell. Others find themselves paralyzed at work when life is in turmoil for other reasons. If you find yourself really badly stuck, it can be helpful to see a psychotherapist. An informal survey suggests that roughly half of the students in our lab see one at some point during their graduate careers. One factor that makes AI harder than most other types of work is that there are no generally accepted standards of progress or of how to evaluate work.