Working, in grad school, and doing an internship.

Okay so obviously by the title I am doing a lot. I have an 8 year old son and he is in private school because where I live the educational system is terrible. My fiancée is a Technical Systems analyst and is salaried but he only makes about $1300 every two weeks. Surprisingly this isn't enough money to help us pay our bills and I am really stressed but trying to hide it for the sake of our family. Does anyone have any suggestions on how to save money or make it stretch in any way? We both have student loans, and car loan payments, as well as the basic bills (rent, electric, etc.). Thank you!