First of all let me tell you that you are one of the few who have the courage. It really takes stamina to be deprived of everything what money give a human: house, family, lifestyle, anything for which you need to pay to have or maintain. The goal is noble: you are going to contribute your time and energy to enriching the human's knowledge with your dissertation and raise your social status by being called Doctor. Lets be frank about the money . the fact that you are a going to be a Doctor, won't mean that you will automatically get richer than if you were, say a Bachelor. So unless your sole focus is not just enriching the human's knowledge with the dissertation, try acquiring skills and knowledge that will help you find a good job, better than the one a Bachelor would find.