Because I had the fabulous luxury of receiving a grant that "forbade me" from taking a job, I spoke with a few people who work full-time while writing their dissertations. They offered this important tip...to finish, occasionally you will need to take time off from your job.
You might need to finish your proposal, write up your field work or move through a difficult writing portion. While ideally you are writing at least two hours a day (rather than just on weekends), sometimes sustained deep writing sessions will be in order.
This might mean thinking ahead now about how you want to use precious vacation time. Truth is, finishing your dissertation or thesis will give you a feeling of peace and relief almost no vacation can provide.
Sarah Federman, PhD