Saturated = Low Productivity?

Have been feeling tired on my job recently. Thinking about it, in the pass one month, I have been working more and more hours in a day, and sometimes even in the weekend. Really feel that I am saturated from work, can't really focus on work especially after the Bangladesh trip. It's a bad cycle thingy, because of tiredness, I feel that I am in my very low productivity level, because of the low productivity, I have to work more hours, and hence feel even more tired... What's the way out from it? I am going for a trip next weekend, but at the moment I am not excited about it at all...What I need now is just a day off, to stay at some cosy place, without any appointments, without any phone calls, without any disturbs and just relax and do nothing at all.