Hi, I am new to this forum and your message was the first one I saw. I am at the end of my first year of a Professional Doctorate so no where near where you are but I can sympathize. I have been told been told that staying power is what you need to successfully complete a PHD. I would have a couple of days off to clear your head, you can't work effectively with a clouded head, and then get back on it. You are closer to the end than you were in the beginning!