Not all Arduinos have EEPROM and in some you have to execute a Write before it is saved. Which one do you have? The Arduino tool chain requires you to commit which writes the data to the pseudo EEPROM. Thanks sterretje, I have been looking at a different set of tools.
The microcontroller on the Arduino boards have 512 bytes of EEPROM: memory whose values are kept when the board is turned off (like a tiny hard drive). There are many (thousands) examples of how to do this on the internet. I do not have the time or inclination to write the code for you. Post your code per the forum recommendations and we will try to help you.